ABMGG General Certification Examination — Questions and Answers

Question 1: In the context of American Board of Medical Genetics and Genomics, what is the primary goal of clinical assessment methods?

Optimal patient outcomes and safety (Correct answer)
Administrative efficiency
Cost reduction for the facility
Provider convenience

Correct answer: Optimal patient outcomes and safety

The primary goal of clinical assessment methods in American Board of Medical Genetics and Genomics is always to achieve optimal patient outcomes while maintaining safety standards.

Question 2: Which evidence-based approach is most important when applying pharmacology basics principles?

Relying solely on textbook guidelines from any era
Integrating current research with clinical expertise and patient values (Correct answer)
Following personal clinical intuition only
Using the most expensive available treatment

Correct answer: Integrating current research with clinical expertise and patient values

Evidence-based practice in ${subj.toLowerCase()} requires integrating current research findings with clinical expertise and individual patient values.

Question 3: What role does documentation play in patient communication?

It only matters for billing purposes
It is optional but recommended
It is a critical legal and clinical requirement (Correct answer)
It is only needed for surgical procedures

Correct answer: It is a critical legal and clinical requirement

Thorough documentation in patient communication is both a legal requirement and essential for continuity of patient care.

Question 4: What role does documentation play in pharmacology basics?

It is a critical legal and clinical requirement (Correct answer)
It is only needed for surgical procedures
It is optional but recommended
It only matters for billing purposes

Correct answer: It is a critical legal and clinical requirement

Thorough documentation in pharmacology basics is both a legal requirement and essential for continuity of patient care.

Question 5: For ABMGG certification in Clinical Genetics and Genomics, the required residency program must be accredited by which organization?

American College of Medical Genetics (ACMG)
Accreditation Council for Graduate Medical Education (ACGME) (Correct answer)
American Medical Association (AMA)
National Institutes of Health (NIH)

Correct answer: Accreditation Council for Graduate Medical Education (ACGME)

The residency or fellowship programs required for ABMGG certification must be accredited by the Accreditation Council for Graduate Medical Education (ACGME).

Question 6: In X-linked dominant inheritance, which statement best describes the pattern of affected individuals?

Only males are affected; females are always unaffected carriers
Only females are affected because males with the variant rarely survive
Both males and females are affected, but males typically have more severe disease (Correct answer)
Transmission occurs exclusively through the maternal line

Correct answer: Both males and females are affected, but males typically have more severe disease

In X-linked dominant conditions, hemizygous males often have more severe disease (sometimes lethal in utero) while heterozygous females are affected but typically less severely.

Question 7: In the context of ABMGG laboratory practice, what is a mosaic variant?

A benign polymorphism present in >1% of the population
A de novo variant found in both parents
A variant spanning two different chromosomes
A variant present in only a subset of an individual's cells (Correct answer)

Correct answer: A variant present in only a subset of an individual's cells

Mosaicism arises when a post-zygotic mutation occurs in a progenitor cell, resulting in two or more genetically distinct cell populations within the same individual.

Question 8: Which type of training is mandatory for ABMGG certification?

Internship at a clinical genetics laboratory
Completion of an accredited residency or fellowship program in genetics/genomics (Correct answer)
On-the-job training in a genetics clinic
Certification in general internal medicine

Correct answer: Completion of an accredited residency or fellowship program in genetics/genomics

ABMGG requires candidates to complete an accredited residency or fellowship program in genetics or genomics to ensure they receive comprehensive training.

Question 9: A copy number variant (CNV) is generally defined as a segment of DNA greater than how many base pairs that shows variation in copy number relative to a reference genome?

50 bp
100 bp
1,000 bp (1 kb) (Correct answer)
500 bp

Correct answer: 1,000 bp (1 kb)

CNVs are conventionally defined as segments ≥1 kb (1,000 bp) that are present at variable copy numbers compared to a reference genome, distinguishing them from smaller insertion/deletion variants.

Question 10: Which of the following best describes the role of ABMGG in healthcare?

Certifying professionals to improve healthcare outcomes (Correct answer)
Accrediting hospitals for genetic services
Ensuring quality education for geneticists
Conducting genetic testing for rare diseases

Correct answer: Certifying professionals to improve healthcare outcomes

ABMGG focuses on certifying professionals in genetics and genomics to maintain high standards, which ultimately contributes to improved healthcare outcomes. It does not conduct testing or accredit hospitals directly.

Question 11: Founder effects in isolated populations increase the prevalence of specific genetic diseases because:

Founder populations mutate genes at higher rates than outbred populations
A small founding population may carry a pathogenic allele at high frequency due to genetic drift (Correct answer)
Isolated populations have reduced recombination leading to larger pathogenic haplotypes
Mating in founder populations selects for heterozygous carriers

Correct answer: A small founding population may carry a pathogenic allele at high frequency due to genetic drift

If a founding individual carried a rare pathogenic allele, it can reach unexpectedly high frequency in descendants due to drift and small effective population size.

Question 12: What role does documentation play in treatment planning?

It is a critical legal and clinical requirement (Correct answer)
It is only needed for surgical procedures
It is optional but recommended
It only matters for billing purposes

Correct answer: It is a critical legal and clinical requirement

Thorough documentation in treatment planning is both a legal requirement and essential for continuity of patient care.

Question 13: How should a practitioner handle an unexpected finding during diagnostic procedures procedures?

Document it and follow established protocols for further evaluation (Correct answer)
Discuss it informally without documenting
Wait to see if it resolves on its own
Ignore it if not related to the primary concern

Correct answer: Document it and follow established protocols for further evaluation

Unexpected findings must be documented and addressed through established protocols to ensure patient safety.

Question 14: Which evidence-based approach is most important when applying clinical assessment methods principles?

Using the most expensive available treatment
Integrating current research with clinical expertise and patient values (Correct answer)
Following personal clinical intuition only
Relying solely on textbook guidelines from any era

Correct answer: Integrating current research with clinical expertise and patient values

Evidence-based practice in ${subj.toLowerCase()} requires integrating current research findings with clinical expertise and individual patient values.

Question 15: A carrier of a balanced reciprocal translocation is at risk of producing offspring with which abnormality?

Offspring with whole-chromosome aneuploidy
Only normal offspring
Only monosomic offspring
Offspring with unbalanced chromosomal segments causing partial monosomy or trisomy (Correct answer)

Correct answer: Offspring with unbalanced chromosomal segments causing partial monosomy or trisomy

During meiosis, a balanced translocation carrier can produce unbalanced gametes through 3:1 or 2:2 segregation, resulting in offspring with partial monosomy or partial trisomy.

Question 16: What does the ABMGG certification signify for a medical geneticist?

Guaranteed employment in a genetics laboratory
A license to practice medicine in the United States
Completion of a doctoral degree in medicine
Mastery of clinical and laboratory genetic practices (Correct answer)

Correct answer: Mastery of clinical and laboratory genetic practices

ABMGG certification signifies that a professional has met rigorous standards and demonstrated mastery in the clinical and laboratory practices of genetics and genomics.

Question 17: Which term describes a variant that arose newly in a patient and is not present in either biological parent?

De novo variant (Correct answer)
Hemizygous variant
Compound heterozygous variant
Synonymous variant

Correct answer: De novo variant

A de novo variant occurs as a new mutation in the proband and is confirmed by demonstrating its absence in both parents via trio sequencing or targeted testing.

Question 18: Which of the following is NOT a focus of training in ABMGG-approved programs?

Ethical considerations in genetic testing
Financial planning for genetic practices (Correct answer)
Laboratory techniques in cytogenetics and molecular genetics
Clinical management of genetic disorders

Correct answer: Financial planning for genetic practices

Training in ABMGG-approved programs focuses on clinical management, laboratory techniques, and ethical considerations, but financial planning is not part of the core curriculum.

Question 19: Which sequencing methodology is used to detect epigenetic modifications such as DNA methylation patterns relevant to imprinting disorders?

Sanger sequencing
SNP array
Short-read whole exome sequencing
Bisulfite sequencing (Correct answer)

Correct answer: Bisulfite sequencing

Bisulfite treatment converts unmethylated cytosines to uracil while leaving methylated cytosines intact, enabling methylation mapping by sequencing.

Question 20: Long-read sequencing technologies (e.g., PacBio, Oxford Nanopore) offer a key advantage over short-read platforms for clinical genomics because they:

Can span repetitive regions and resolve complex structural variants (Correct answer)
Are less expensive per gigabase than Illumina sequencing
Require less DNA input than short-read platforms
Provide lower error rates per base than short reads

Correct answer: Can span repetitive regions and resolve complex structural variants

Long reads can traverse repetitive DNA, phasing variants and characterizing structural rearrangements that short reads cannot span.

Question 21: What is a key component of ABMGG's certification process?

Mandatory publication of research
Board review by the American Medical Association
Completion of a patient advocacy course
Passing a comprehensive examination (Correct answer)

Correct answer: Passing a comprehensive examination

Certification by ABMGG requires candidates to pass a rigorous examination that tests their knowledge and skills in genetics and genomics. Publication and AMA review are not part of their certification process.

Question 22: What is the standard of care requirement for diagnostic procedures in clinical practice?

Whatever the practitioner feels is adequate
The minimum effort needed to avoid a lawsuit
The level of care a reasonably competent practitioner would provide (Correct answer)
The most aggressive treatment available

Correct answer: The level of care a reasonably competent practitioner would provide

The standard of care is defined as what a reasonably competent practitioner with similar training would provide under similar circumstances.

Question 23: Fluorescence in situ hybridization (FISH) is best suited for detecting which type of chromosomal abnormality?

Submicroscopic deletions at targeted loci (Correct answer)
Balanced reciprocal translocations with no copy number change
Whole genome aneuploidy
Polyploidy

Correct answer: Submicroscopic deletions at targeted loci

FISH uses locus-specific probes to detect submicroscopic deletions or duplications at targeted regions that are too small to be seen by conventional karyotyping.

Question 24: What does the coefficient of relationship (r) quantify in genetic counseling for consanguineous couples?

The proportion of genes shared identical by descent between two related individuals (Correct answer)
The percentage of the genome covered by runs of homozygosity
The number of generations separating two individuals in a pedigree
The probability that a pathogenic variant will be expressed in offspring

Correct answer: The proportion of genes shared identical by descent between two related individuals

The coefficient of relationship r = 2F, where F is the inbreeding coefficient; for first cousins r = 0.125, meaning they share ~12.5% of their genome by descent.

Question 25: Which concept explains why two siblings with the same pathogenic CFTR genotype can have markedly different disease severity?

Reduced penetrance
Locus heterogeneity
Genetic anticipation
Variable expressivity (Correct answer)

Correct answer: Variable expressivity

Variable expressivity refers to the range of signs and symptoms that can occur in individuals with the same pathogenic genotype, influenced by modifier genes and environment.

Question 26: Which chromosomal microarray platform approach is required by ACMG guidelines for the evaluation of individuals with unexplained developmental delay, intellectual disability, autism spectrum disorder, or multiple congenital anomalies?

FISH panel alone
G-banded karyotype alone
Whole exome sequencing alone
Chromosomal microarray analysis (CMA) as a first-tier test (Correct answer)

Correct answer: Chromosomal microarray analysis (CMA) as a first-tier test

ACMG recommends CMA as the first-tier cytogenetic diagnostic test for individuals with unexplained DD/ID, ASD, or MCA because it detects submicroscopic CNVs missed by conventional karyotyping.

Question 27: Fragile X syndrome is caused by a CGG trinucleotide repeat expansion in the promoter region of which gene?

DMPK
ATM
FMR1 (Correct answer)
HTT

Correct answer: FMR1

Fragile X syndrome results from a >200 CGG repeat expansion (full mutation) in the 5' UTR of FMR1 on the X chromosome, leading to gene silencing via methylation.

Question 28: The most common cause of trisomy 21 (Down syndrome) is:

Meiotic nondisjunction (Correct answer)
Mosaicism
Uniparental disomy
Robertsonian translocation

Correct answer: Meiotic nondisjunction

Approximately 95% of Down syndrome cases result from meiotic nondisjunction, most often in maternal meiosis I, leading to a gamete with two copies of chromosome 21.

Question 29: What does fluorescence in situ hybridization (FISH) detect that a standard G-banded karyotype typically cannot?

Whole chromosome aneuploidy
Polyploidy
Submicroscopic deletions at specific loci (Correct answer)
Large chromosomal translocations

Correct answer: Submicroscopic deletions at specific loci

FISH uses labeled probes to detect deletions or duplications at targeted loci below the ~5–10 Mb resolution of conventional karyotyping.

Question 30: Which prenatal cytogenetic technique provides the earliest diagnostic result for chromosomal abnormalities, typically performed at 10–13 weeks gestation?

Cell-free fetal DNA (cfDNA) karyotyping
Chorionic villus sampling (CVS) (Correct answer)
Amniocentesis
Cordocentesis

Correct answer: Chorionic villus sampling (CVS)

CVS is performed at 10–13 weeks and provides fetal chromosomal material earlier than amniocentesis (15–20 weeks) or cordocentesis (18+ weeks).

Question 31: A pathogenic variant classified as 'likely pathogenic' under ACMG/AMP guidelines has what minimum probability of being disease-causing?

Greater than 50%
Greater than 75%
Greater than 90% (Correct answer)
Greater than 99%

Correct answer: Greater than 90%

The ACMG/AMP framework defines 'likely pathogenic' as >90% probability of pathogenicity based on the combined evidence criteria scored.

Question 32: Constitutional chromosomal abnormalities differ from somatic (acquired) chromosomal changes primarily in that constitutional changes are:

Present in every nucleated cell of the body and inherited through the germline (Correct answer)
Limited to hematopoietic cells
Detectable only by next-generation sequencing
Always more severe clinically

Correct answer: Present in every nucleated cell of the body and inherited through the germline

Constitutional chromosomal abnormalities arise during gametogenesis or early embryogenesis and are therefore present in virtually every cell of the body, whereas somatic changes arise post-zygotically in specific tissues.

Question 33: Which ethical principle is most directly applicable to clinical assessment methods?

Maximize facility revenue
Beneficence — acting in the patient's best interest (Correct answer)
Prioritize speed over thoroughness
Follow the most convenient protocol

Correct answer: Beneficence — acting in the patient's best interest

Beneficence, the principle of acting in the patient's best interest, is fundamental to ethical practice in clinical assessment methods.

Question 34: Which evidence-based approach is most important when applying patient communication principles?

Relying solely on textbook guidelines from any era
Integrating current research with clinical expertise and patient values (Correct answer)
Using the most expensive available treatment
Following personal clinical intuition only

Correct answer: Integrating current research with clinical expertise and patient values

Evidence-based practice in ${subj.toLowerCase()} requires integrating current research findings with clinical expertise and individual patient values.

Question 35: Which next-generation sequencing approach sequences all protein-coding regions of the genome and is commonly used in ABMGG clinical practice?

Chromosomal microarray
Whole exome sequencing (Correct answer)
Methylation array
RNA sequencing

Correct answer: Whole exome sequencing

Whole exome sequencing targets the ~1–2% of the genome that encodes proteins and is a primary clinical tool for diagnosing rare Mendelian disorders.

Question 36: Which evidence-based approach is most important when applying diagnostic procedures principles?

Relying solely on textbook guidelines from any era
Integrating current research with clinical expertise and patient values (Correct answer)
Using the most expensive available treatment
Following personal clinical intuition only

Correct answer: Integrating current research with clinical expertise and patient values

Evidence-based practice in ${subj.toLowerCase()} requires integrating current research findings with clinical expertise and individual patient values.

Question 37: Which ethical principle is most directly applicable to treatment planning?

Maximize facility revenue
Prioritize speed over thoroughness
Beneficence — acting in the patient's best interest (Correct answer)
Follow the most convenient protocol

Correct answer: Beneficence — acting in the patient's best interest

Beneficence, the principle of acting in the patient's best interest, is fundamental to ethical practice in treatment planning.

Question 38: Which bioinformatics database is most commonly used by ABMGG-certified clinical laboratory geneticists to interpret variant pathogenicity?

GenBank
ClinVar (Correct answer)
OMIM only
PubMed

Correct answer: ClinVar

ClinVar is the NIH-hosted repository of variant–disease interpretations submitted by clinical laboratories and is integral to ACMG/AMP variant classification guidelines.

Question 39: Why is continuing medical (CME) important for ABMGG-certified professionals?

It ensures professionals stay informed about evolving medical practices in genetics (Correct answer)
It focuses on teaching new genetic research methodologies exclusively.
It satisfies state licensure requirements only
It replaces the need for re-certification exams

Correct answer: It ensures professionals stay informed about evolving medical practices in genetics

CME helps professionals remain updated on the latest medical and technological advancements in genetics, which is essential for providing high-quality patient care.

Question 40: What is the purpose of completing an ABMGG-accredited fellowship program?

To gain specialized training in genetic counseling
To obtain a master’s degree in genetics
To secure funding for genetic research
To meet eligibility requirements for ABMGG board certification (Correct answer)

Correct answer: To meet eligibility requirements for ABMGG board certification

Completing an ABMGG-accredited fellowship is required to satisfy the eligibility criteria for board certification by the American Board of Medical Genetics and Genomics. Fellowship training is clinical and scientific in nature—it does not confer a master's degree, provide research funding, or substitute for genetic counseling certification, which is a separate credential with its own pathway.

Question 41: Locus heterogeneity in genetic disease means that:

The same mutation causes different phenotypes in different individuals
Two alleles at the same locus both carry pathogenic variants
A single gene has multiple pathogenic variants
Mutations in different genes can cause the same clinical phenotype (Correct answer)

Correct answer: Mutations in different genes can cause the same clinical phenotype

Locus heterogeneity describes when mutations at distinct chromosomal loci produce an indistinguishable phenotype, as seen in retinitis pigmentosa with >70 causative genes.

Question 42: Multiplex ligation-dependent probe amplification (MLPA) is primarily used in clinical genetics to:

Quantify copy number at specific gene loci using probe signals (Correct answer)
Sequence the full coding region of a gene
Perform genome-wide variant discovery
Detect DNA methylation at CpG islands

Correct answer: Quantify copy number at specific gene loci using probe signals

MLPA uses pairs of probes that ligate and amplify only when both hybridize adjacently, allowing quantification of up to 50 loci in a single reaction.

Question 43: What term describes the phenomenon where carrier females of an X-linked recessive condition are clinically affected due to skewed X-inactivation?

Compound heterozygote
Obligate carrier
Hemizygous affected
Manifesting carrier (Correct answer)

Correct answer: Manifesting carrier

When the normal X chromosome is preferentially inactivated in most cells, the carrier female expresses the disease to varying degrees and is called a manifesting carrier.

Question 44: RNA sequencing (RNA-seq) adds clinical value in medical genetics primarily by:

Measuring protein levels directly
Replacing whole genome sequencing for SNV detection
Detecting copy number variants with higher resolution than CMA
Identifying splicing defects and allele-specific expression abnormalities (Correct answer)

Correct answer: Identifying splicing defects and allele-specific expression abnormalities

RNA-seq can reveal aberrant splicing caused by deep intronic variants and confirm whether a variant affects gene expression, increasing diagnostic yield.

Question 45: What is the standard of care requirement for pharmacology basics in clinical practice?

The level of care a reasonably competent practitioner would provide (Correct answer)
The minimum effort needed to avoid a lawsuit
Whatever the practitioner feels is adequate
The most aggressive treatment available

Correct answer: The level of care a reasonably competent practitioner would provide

The standard of care is defined as what a reasonably competent practitioner with similar training would provide under similar circumstances.

Question 46: What is the genetic basis of anticipation, seen in conditions such as myotonic dystrophy?

Accumulation of somatic mutations over a lifetime
Increasing penetrance of a dominant allele with parental age
Progressive loss of imprinting marks through meiosis
Expansion of unstable trinucleotide repeats with each generation (Correct answer)

Correct answer: Expansion of unstable trinucleotide repeats with each generation

Unstable repeat tracts tend to expand during meiosis; larger repeat sizes correlate with earlier onset and more severe disease in successive generations.

Question 47: Which subspecialty certification is overseen by ABMGG?

Epidemiology
Pediatric Surgery
Laboratory Genetics and Genomics (Correct answer)
Molecular Pathology

Correct answer: Laboratory Genetics and Genomics

ABMGG offers certification in several subspecialties, including Laboratory Genetics and Genomics. Pediatric surgery, molecular pathology, and epidemiology fall under other medical boards or fields.

Question 48: In the context of American Board of Medical Genetics and Genomics, what is the primary goal of diagnostic procedures?

Administrative efficiency
Provider convenience
Cost reduction for the facility
Optimal patient outcomes and safety (Correct answer)

Correct answer: Optimal patient outcomes and safety

The primary goal of diagnostic procedures in American Board of Medical Genetics and Genomics is always to achieve optimal patient outcomes while maintaining safety standards.

Question 49: What role does documentation play in patient safety protocols?

It only matters for billing purposes
It is only needed for surgical procedures
It is a critical legal and clinical requirement (Correct answer)
It is optional but recommended

Correct answer: It is a critical legal and clinical requirement

Thorough documentation in patient safety protocols is both a legal requirement and essential for continuity of patient care.

Question 50: When reporting a Robertsonian translocation between chromosomes 13 and 14, the correct ISCN notation for a carrier with 45 chromosomes is:

46,XY,t(13;14)
45,XY,rob(13;14)(q10;q10) (Correct answer)
46,XY,rob(13q14q)
45,XY,der(13;14)

Correct answer: 45,XY,rob(13;14)(q10;q10)

ISCN uses rob() to denote Robertsonian translocations; 45,XY,rob(13;14)(q10;q10) correctly indicates a male carrier with 45 chromosomes due to fusion of acrocentric chromosomes 13 and 14 at their centromeres.

Question 51: Which banding technique is most commonly used to produce a standard karyotype in clinical cytogenetics laboratories?

G-banding (Correct answer)
R-banding
Q-banding
C-banding

Correct answer: G-banding

G-banding (Giemsa banding) is the standard technique used in clinical cytogenetics to produce a karyotype with characteristic dark and light band patterns.

Question 52: Which ethical principle is most directly applicable to patient communication?

Follow the most convenient protocol
Prioritize speed over thoroughness
Maximize facility revenue
Beneficence — acting in the patient's best interest (Correct answer)

Correct answer: Beneficence — acting in the patient's best interest

Beneficence, the principle of acting in the patient's best interest, is fundamental to ethical practice in patient communication.

Question 53: Which evidence-based approach is most important when applying documentation standards principles?

Following personal clinical intuition only
Using the most expensive available treatment
Integrating current research with clinical expertise and patient values (Correct answer)
Relying solely on textbook guidelines from any era

Correct answer: Integrating current research with clinical expertise and patient values

Evidence-based practice in ${subj.toLowerCase()} requires integrating current research findings with clinical expertise and individual patient values.

Question 54: What is the clinical significance of a homozygous deletion detected by chromosomal microarray in a consanguineous family?

It may unmask a recessive pathogenic variant, indicating autozygosity by descent (Correct answer)
It is invariably benign if the deletion is small
It always indicates a de novo chromosomal rearrangement
It confirms a dominant condition with complete penetrance

Correct answer: It may unmask a recessive pathogenic variant, indicating autozygosity by descent

Regions of homozygosity in consanguineous families often reflect identity by descent, increasing the probability that a pathogenic recessive allele is present in two copies.

Question 55: According to the ISCN (International System for Human Cytogenomic Nomenclature), how is a male with trisomy 21 correctly written?

46,XY,+21
47,XY,+21 (Correct answer)
46,XY,21q+
47,XX,+21

Correct answer: 47,XY,+21

47,XY,+21 indicates a male (XY) with 47 total chromosomes due to an extra chromosome 21, which is the correct ISCN notation for Down syndrome in a male.

Question 56: What role does documentation play in diagnostic procedures?

It only matters for billing purposes
It is only needed for surgical procedures
It is optional but recommended
It is a critical legal and clinical requirement (Correct answer)

Correct answer: It is a critical legal and clinical requirement

Thorough documentation in diagnostic procedures is both a legal requirement and essential for continuity of patient care.

Question 57: A de novo pathogenic variant in a gene causes severe disease in a proband whose parents are unaffected. What is the approximate recurrence risk for future siblings?

Near 0% with no residual risk
25% consistent with autosomal recessive
50% consistent with autosomal dominant
1–2% due to possible germline mosaicism in a parent (Correct answer)

Correct answer: 1–2% due to possible germline mosaicism in a parent

Even when neither parent shows the variant by blood testing, low-level germline mosaicism in a parent can raise sibling recurrence risk to ~1–2%.

Question 58: In pharmacogenomics, which cytochrome P450 enzyme polymorphisms are most commonly assessed to guide drug dosing decisions in clinical genetics?

CYP1A1 and CYP3A7
CYP11B1 and CYP21A2
CYP2D6 and CYP2C19 (Correct answer)
CYP27B1 and CYP24A1

Correct answer: CYP2D6 and CYP2C19

CYP2D6 and CYP2C19 metabolize a large proportion of commonly prescribed drugs; variants in these genes cause poor-metabolizer or ultra-rapid-metabolizer phenotypes.

Question 59: A chromosomal microarray (CMA) using SNP probes has an advantage over array CGH in that it can detect:

Telomeric fusions
Balanced translocations
Uniparental disomy (UPD) (Correct answer)
Larger deletions

Correct answer: Uniparental disomy (UPD)

SNP-based arrays can identify stretches of homozygosity that indicate uniparental disomy, which array CGH cannot detect because UPD does not involve copy number change.

Question 60: Chromosomal instability syndromes such as Bloom syndrome, Fanconi anemia, and ataxia-telangiectasia share which cytogenetic hallmark?

Increased frequency of chromosomal breaks and rearrangements (Correct answer)
Supernumerary marker chromosomes
Consistent trisomy of a specific autosome
Constitutional monosomy

Correct answer: Increased frequency of chromosomal breaks and rearrangements

These syndromes are caused by defects in DNA repair pathways, resulting in elevated rates of chromosomal breaks, sister chromatid exchanges, and structural rearrangements detectable cytogenetically.

Question 61: Chromosomal mosaicism in a patient is BEST defined as:

Copy number variation between maternal and paternal alleles
A heterozygous deletion detectable by FISH
Two different chromosomal structural variants in the same cell
The presence of two or more cytogenetically distinct cell lines from the same zygote (Correct answer)

Correct answer: The presence of two or more cytogenetically distinct cell lines from the same zygote

Mosaicism is the coexistence of two or more cell populations with different chromosomal constitutions arising from a single zygote, typically due to a post-zygotic mitotic error.

Question 62: Which ethical principle is most directly applicable to pharmacology basics?

Prioritize speed over thoroughness
Follow the most convenient protocol
Beneficence — acting in the patient's best interest (Correct answer)
Maximize facility revenue

Correct answer: Beneficence — acting in the patient's best interest

Beneficence, the principle of acting in the patient's best interest, is fundamental to ethical practice in pharmacology basics.

Question 63: Turner syndrome (45,X) most commonly results from loss of the sex chromosome derived from which parent?

Paternal X is retained; maternal sex chromosome is lost
Equal frequency from either parent
Maternal X is retained; paternal sex chromosome is lost (Correct answer)
Always due to maternal nondisjunction

Correct answer: Maternal X is retained; paternal sex chromosome is lost

Studies show that in ~75% of 45,X cases the retained X is of maternal origin, meaning the paternal sex chromosome (X or Y) was lost.

Question 64: Which ethical principle is most directly applicable to diagnostic procedures?

Follow the most convenient protocol
Beneficence — acting in the patient's best interest (Correct answer)
Maximize facility revenue
Prioritize speed over thoroughness

Correct answer: Beneficence — acting in the patient's best interest

Beneficence, the principle of acting in the patient's best interest, is fundamental to ethical practice in diagnostic procedures.

Question 65: Genomic imprinting results in disease when:

Both copies of a gene are inherited from the same parent (uniparental disomy) or one copy's imprint is erased (Correct answer)
A recessive variant occurs in compound heterozygous form
A dominant allele fails to be expressed due to low penetrance
Trinucleotide repeats expand during maternal transmission only

Correct answer: Both copies of a gene are inherited from the same parent (uniparental disomy) or one copy's imprint is erased

Imprinted genes are expressed from only one parental allele; uniparental disomy or imprinting center defects silence both working copies, causing disease.

Question 66: What is the primary purpose of the Maintenance of Certification (MOC) program in ABMGG?

To replace the initial certification exam
To assess the clinical efficiency of geneticists through peer-reviewed publications
To ensure professionals remain up-to-date with advancements in genetics and genomics (Correct answer)
To validate the financial standing of certified professionals

Correct answer: To ensure professionals remain up-to-date with advancements in genetics and genomics

The MOC program is designed to keep certified professionals updated on the latest advancements in genetics and genomics through ongoing education, self-assessment, and re-certification.

Question 67: What ethical responsibility is emphasized for ABMGG-certified professionals?

Ensuring patient confidentiality and informed consent (Correct answer)
Submitting genetic data to public databases without restrictions
Prioritizing research over clinical duties
Conducting genetic testing for all patients regardless of consent

Correct answer: Ensuring patient confidentiality and informed consent

Ethical practice, including maintaining patient confidentiality and obtaining informed consent, is a cornerstone of professional standards for ABMGG-certified professionals.

Question 68: What is the standard of care requirement for treatment planning in clinical practice?

The minimum effort needed to avoid a lawsuit
Whatever the practitioner feels is adequate
The level of care a reasonably competent practitioner would provide (Correct answer)
The most aggressive treatment available

Correct answer: The level of care a reasonably competent practitioner would provide

The standard of care is defined as what a reasonably competent practitioner with similar training would provide under similar circumstances.

Question 69: Hardy-Weinberg equilibrium predicts allele frequencies in a population remain stable under which set of conditions?

Random mating, small population, founder effect, no migration
Inbreeding, large population size, selective pressure, high mutation rate
Random mating, no mutation, no selection, no genetic drift, no gene flow (Correct answer)
Non-random mating, no selection, equal sex ratio, high recombination

Correct answer: Random mating, no mutation, no selection, no genetic drift, no gene flow

Hardy-Weinberg equilibrium holds only when five conditions are met: random mating, no mutation, no natural selection, infinite population size, and no migration.

Question 70: Spectral karyotyping (SKY) and multicolor FISH (M-FISH) are especially useful for identifying:

Complex chromosomal rearrangements and marker chromosomes of unknown origin (Correct answer)
Point mutations within a gene
Repeat expansion disorders
SNP-level variants

Correct answer: Complex chromosomal rearrangements and marker chromosomes of unknown origin

SKY/M-FISH uses combinatorial labeling with multiple fluorochromes to paint each chromosome a unique color, making it ideal for characterizing complex rearrangements and small marker chromosomes.

Question 71: Array comparative genomic hybridization (aCGH) detects copy number variants (CNVs) by comparing:

Patient DNA methylation to a reference panel
Sequence reads from patient DNA to a reference genome
Hybridization intensity of patient DNA vs. a reference DNA on oligonucleotide probes (Correct answer)
Patient RNA expression levels to normal tissue

Correct answer: Hybridization intensity of patient DNA vs. a reference DNA on oligonucleotide probes

In aCGH, differentially labeled patient and reference DNAs are co-hybridized to probes on a microarray; the ratio of fluorescence intensities reveals gains (duplications) or losses (deletions) in the patient.

Question 72: Which genomic technique is considered most appropriate as a first-tier test for a child with unexplained intellectual disability and dysmorphic features in current US clinical practice?

Chromosomal microarray (Correct answer)
Targeted single-gene Sanger sequencing
G-banded karyotype
Mitochondrial genome sequencing

Correct answer: Chromosomal microarray

Professional guidelines from ACMG and AAP recommend chromosomal microarray as the first-tier cytogenomic test for unexplained intellectual disability and multiple congenital anomalies.

Question 73: In the context of American Board of Medical Genetics and Genomics, what is the primary goal of treatment planning?

Optimal patient outcomes and safety (Correct answer)
Administrative efficiency
Cost reduction for the facility
Provider convenience

Correct answer: Optimal patient outcomes and safety

The primary goal of treatment planning in American Board of Medical Genetics and Genomics is always to achieve optimal patient outcomes while maintaining safety standards.

Question 74: What is the minimum educational qualification required to apply for ABMGG certification?

Bachelor’s degree in Genetics
Doctoral degree (e.g., MD, DO, or PhD) in a relevant field (Correct answer)
Associate’s degree in Healthcare Management
Master’s degree in Molecular Biology

Correct answer: Doctoral degree (e.g., MD, DO, or PhD) in a relevant field

To qualify for ABMGG certification, candidates must have a doctoral degree (e.g., MD, DO, or PhD) in a medical or related scientific field relevant to genetics and genomics.

Question 75: Whole genome sequencing (WGS) detects which class of variants that whole exome sequencing (WES) routinely misses?

Frameshift variants in coding exons
Deep intronic and regulatory region variants (Correct answer)
Coding single nucleotide variants
Small insertions and deletions in exons

Correct answer: Deep intronic and regulatory region variants

WES captures only exons; WGS covers introns, promoters, and other regulatory regions where disease-causing variants can reside.

Question 76: Which of the following is NOT a requirement for maintaining certification through ABMGG?

Passing periodic knowledge assessments
Engaging in self-assessment modules
Publishing a peer-reviewed research paper every year (Correct answer)
Participation in continuing medical education (CME)

Correct answer: Publishing a peer-reviewed research paper every year

While ABMGG requires CME and knowledge assessments as part of MOC, publishing research papers is not mandatory for maintaining certification.

Question 77: Which of the following is NOT an advocacy initiative supported by ABMGG?

Supporting ethical practices in genetic testing
Educating policymakers on the role of genetics in healthcare
Mandating genetic testing for all newborns (Correct answer)
Increasing access to certified genetic professionals

Correct answer: Mandating genetic testing for all newborns

ABMGG supports education, ethical practices, and access to genetic services but does not advocate for mandatory genetic testing without appropriate guidelines and consent.

Question 78: What is the standard of care requirement for documentation standards in clinical practice?

The minimum effort needed to avoid a lawsuit
The level of care a reasonably competent practitioner would provide (Correct answer)
Whatever the practitioner feels is adequate
The most aggressive treatment available

Correct answer: The level of care a reasonably competent practitioner would provide

The standard of care is defined as what a reasonably competent practitioner with similar training would provide under similar circumstances.

Question 79: What is the standard of care requirement for clinical assessment methods in clinical practice?

The most aggressive treatment available
The minimum effort needed to avoid a lawsuit
The level of care a reasonably competent practitioner would provide (Correct answer)
Whatever the practitioner feels is adequate

Correct answer: The level of care a reasonably competent practitioner would provide

The standard of care is defined as what a reasonably competent practitioner with similar training would provide under similar circumstances.

Question 80: What role does documentation play in medical ethics and law?

It is a critical legal and clinical requirement (Correct answer)
It is only needed for surgical procedures
It only matters for billing purposes
It is optional but recommended

Correct answer: It is a critical legal and clinical requirement

Thorough documentation in medical ethics and law is both a legal requirement and essential for continuity of patient care.

Question 81: Which molecular technique is the gold standard for confirming the size of trinucleotide repeat expansions such as those in Huntington disease?

Chromosomal microarray
Southern blot analysis (Correct answer)
FISH
Whole genome sequencing

Correct answer: Southern blot analysis

Southern blot can accurately size large repeat expansions that PCR-based methods may fail to amplify through, making it the confirmatory standard.

Question 82: What role does documentation play in clinical assessment methods?

It is optional but recommended
It is a critical legal and clinical requirement (Correct answer)
It is only needed for surgical procedures
It only matters for billing purposes

Correct answer: It is a critical legal and clinical requirement

Thorough documentation in clinical assessment methods is both a legal requirement and essential for continuity of patient care.

Question 83: Uniparental disomy (UPD) can cause disease even when both copies of a chromosome are structurally normal primarily because of:

Loss of heterozygosity for oncogenes
Genomic imprinting causing silencing of maternally or paternally imprinted genes (Correct answer)
Increased recombination frequency
Dosage imbalance from two copies of one chromosome

Correct answer: Genomic imprinting causing silencing of maternally or paternally imprinted genes

Genomic imprinting silences certain genes depending on parental origin; UPD can result in either two silenced (imprinted) copies or two expressed copies, disrupting normal gene dosage for imprinted loci.

Question 84: What is the primary mission of the ABMGG?

Conduct genetic research
Promote public awareness of hereditary diseases
Develop and administer medical school curricula
Certify medical professionals in genetics and genomics (Correct answer)

Correct answer: Certify medical professionals in genetics and genomics

The ABMGG's core mission is to certify professionals in genetics and genomics, ensuring they meet rigorous standards of knowledge and skill. It does not directly promote public awareness or conduct research, although its certified professionals contribute to these areas.

Question 85: Which inheritance pattern is characterized by transmission exclusively through the maternal line with variable expressivity among family members?

X-linked recessive inheritance
Y-linked inheritance
Autosomal dominant with reduced penetrance
Mitochondrial inheritance (Correct answer)

Correct answer: Mitochondrial inheritance

Mitochondrial DNA is maternally inherited; all children of an affected mother may be affected but paternal transmission never occurs.

Question 86: What is the primary purpose of chromosomal microarray analysis (CMA) in medical genetics?

Detecting copy number variants across the genome (Correct answer)
Measuring RNA expression levels
Sequencing individual gene exons
Identifying trinucleotide repeat expansions

Correct answer: Detecting copy number variants across the genome

CMA detects submicroscopic deletions and duplications (copy number variants) that are below the resolution of conventional karyotyping.

Question 87: In cancer cytogenetics, a deletion of 17p13.1 is most associated with loss of function of which tumor suppressor gene?

APC
TP53 (Correct answer)
BRCA1
RB1

Correct answer: TP53

TP53, which encodes the p53 tumor suppressor protein, is located at 17p13.1, and its deletion or mutation is one of the most common alterations across many cancers.

Question 88: In ABMGG genomic practice, a variant of uncertain significance (VUS) is best managed by:

Immediately reporting it as pathogenic to the ordering clinician
Performing segregation analysis in affected family members (Correct answer)
Ignoring it because it has no clinical significance
Treating the patient based on the VUS alone

Correct answer: Performing segregation analysis in affected family members

Segregation analysis—checking whether the VUS cosegregates with disease in family members—is the primary strategy to reclassify a VUS toward pathogenic or benign.

Question 89: The ACMG/AMP 2015 framework classifies sequence variants into how many categories?

5 (Correct answer)
3
4
7

Correct answer: 5

The five categories are: pathogenic, likely pathogenic, uncertain significance, likely benign, and benign.

Question 90: In autosomal dominant inheritance, what is the recurrence risk for each offspring of an affected parent?

25%
100%
50% (Correct answer)
0%

Correct answer: 50%

An affected parent carries one pathogenic allele on one of the two autosomes; each child has a 50% chance of inheriting that allele.

Question 91: In the context of American Board of Medical Genetics and Genomics, what is the primary goal of pharmacology basics?

Optimal patient outcomes and safety (Correct answer)
Provider convenience
Administrative efficiency
Cost reduction for the facility

Correct answer: Optimal patient outcomes and safety

The primary goal of pharmacology basics in American Board of Medical Genetics and Genomics is always to achieve optimal patient outcomes while maintaining safety standards.

Question 92: Somatic mosaicism for a gain-of-function pathogenic variant in a parent can lead to which outcome in their offspring?

A child with full germline heterozygosity and more severe disease than the mosaic parent (Correct answer)
A child who is always unaffected because mosaicism is never transmitted
Transmission only through the maternal germline
Equal probability of transmitting the variant as a non-mosaic parent

Correct answer: A child with full germline heterozygosity and more severe disease than the mosaic parent

If the variant is in the parent's germline cells, it can be transmitted as a fully heterozygous allele to the child, who then expresses the full phenotype.

Question 93: A pericentric inversion involves a chromosomal segment that:

Results in a ring chromosome
Involves only the short arm
Does not include the centromere
Spans the centromere, including both arms (Correct answer)

Correct answer: Spans the centromere, including both arms

A pericentric inversion includes the centromere, with breakpoints in both the short (p) and long (q) arms, potentially changing the chromosome's arm ratio.

Question 94: How should a practitioner handle an unexpected finding during clinical assessment methods procedures?

Discuss it informally without documenting
Document it and follow established protocols for further evaluation (Correct answer)
Ignore it if not related to the primary concern
Wait to see if it resolves on its own

Correct answer: Document it and follow established protocols for further evaluation

Unexpected findings must be documented and addressed through established protocols to ensure patient safety.

Question 95: The Philadelphia chromosome, found in chronic myelogenous leukemia (CML), results from which chromosomal rearrangement?

Inversion of chromosome 9
Trisomy 9
Reciprocal translocation t(9;22)(q34;q11.2) (Correct answer)
Deletion of chromosome 22q

Correct answer: Reciprocal translocation t(9;22)(q34;q11.2)

The Philadelphia chromosome is formed by t(9;22)(q34;q11.2), which fuses BCR on chromosome 22 with ABL1 on chromosome 9 to create the oncogenic BCR::ABL1 fusion gene.

Question 96: What is the standard of care requirement for medical ethics and law in clinical practice?

The minimum effort needed to avoid a lawsuit
The level of care a reasonably competent practitioner would provide (Correct answer)
Whatever the practitioner feels is adequate
The most aggressive treatment available

Correct answer: The level of care a reasonably competent practitioner would provide

The standard of care is defined as what a reasonably competent practitioner with similar training would provide under similar circumstances.

Question 97: What inheritance pattern is most consistent with a pedigree showing only males affected across multiple generations, with transmission exclusively through daughters who are unaffected?

Autosomal recessive
X-linked recessive (Correct answer)
Mitochondrial
Autosomal dominant

Correct answer: X-linked recessive

In X-linked recessive disease, carrier females pass the mutant X to 50% of sons (affected) and 50% of daughters (carriers), with no male-to-male transmission.

Question 98: Which parameter describes the proportion of individuals with a pathogenic genotype who manifest clinical features of the associated disease?

Expressivity
Pleiotropy
Heritability
Penetrance (Correct answer)

Correct answer: Penetrance

Penetrance is defined as the proportion of individuals with the causative genotype who show any sign of the associated phenotype.

Question 99: In the context of American Board of Medical Genetics and Genomics, what is the primary goal of medical ethics and law?

Cost reduction for the facility
Optimal patient outcomes and safety (Correct answer)
Administrative efficiency
Provider convenience

Correct answer: Optimal patient outcomes and safety

The primary goal of medical ethics and law in American Board of Medical Genetics and Genomics is always to achieve optimal patient outcomes while maintaining safety standards.

Question 100: A couple is each a carrier of the same autosomal recessive variant. What is the probability that their child will be an unaffected carrier?

50% (Correct answer)
25%
75%
0%

Correct answer: 50%

In a carrier × carrier cross, the expected genotypic ratio is 1 homozygous normal : 2 carriers : 1 affected, so carriers make up 2/4 = 50% of offspring.

ABMGG General Certification Examination

The ABMGG General Certification Examination tests foundational knowledge in medical genetics and genomics required for initial board certification. It covers 11 content domains including inheritance patterns, cytogenetics, reproductive genetics, cancer genetics, and genomics.

100

Questions

120 min

Time Limit

70%

To Pass

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