CDN Nutritional Genomics & Precision 2 — Questions and Answers
Question 1: Which single nucleotide polymorphism (SNP) in the MTHFR gene is most commonly associated with reduced folate metabolism?
- C677T (Correct answer)
- A1298C
- G80A
- T1317C
Correct answer: C677T
The MTHFR C677T polymorphism reduces enzyme activity by up to 70% in homozygotes, impairing folate conversion to its active form.
Question 2: Nutrigenomics differs from nutrigenetics primarily in that nutrigenomics focuses on:
- How genetic variation affects individual nutrient response
- How nutrients alter gene expression patterns (Correct answer)
- Identifying SNPs linked to chronic disease
- Measuring genetic predisposition to obesity
Correct answer: How nutrients alter gene expression patterns
Nutrigenomics studies how dietary components influence gene expression, while nutrigenetics examines how genetic variation shapes individual responses to nutrients.
Question 3: A patient with the APOE ε4 allele would most benefit from which dietary intervention based on genetic evidence?
- Increased omega-6 fatty acid intake
- Reduced saturated fat intake (Correct answer)
- High-dose beta-carotene supplementation
- Increased dietary cholesterol
Correct answer: Reduced saturated fat intake
APOE ε4 carriers show greater LDL cholesterol elevations in response to saturated fat compared to APOE ε3 carriers.
Question 4: Which term describes the study of heritable changes in gene expression that do not involve alterations to the DNA sequence?
- Proteomics
- Metabolomics
- Epigenomics (Correct answer)
- Transcriptomics
Correct answer: Epigenomics
Epigenomics examines modifications such as DNA methylation and histone acetylation that regulate gene expression without changing nucleotide sequences.
Question 5: The FTO gene rs9939609 variant is most strongly associated with increased risk of:
- Lactose intolerance
- Celiac disease
- Obesity and elevated BMI (Correct answer)
- Iron-deficiency anemia
Correct answer: Obesity and elevated BMI
The FTO rs9939609 A allele is one of the most replicated genetic variants associated with higher BMI and obesity susceptibility.
Question 6: DNA methylation of gene promoter regions most commonly results in:
- Increased transcription factor binding
- Gene silencing (Correct answer)
- Histone hyperacetylation
- mRNA stabilization
Correct answer: Gene silencing
Methylation of CpG islands in promoter regions physically blocks transcription factor access, leading to gene silencing.
Question 7: Which dietary component is best known for inducing histone acetylation and activating anti-inflammatory genes?
- Saturated fatty acids
- Refined carbohydrates
- Butyrate from fermentable fiber (Correct answer)
- Trans fatty acids
Correct answer: Butyrate from fermentable fiber
Butyrate, a short-chain fatty acid produced from fermentable fiber fermentation, inhibits histone deacetylases (HDACs), promoting histone acetylation and gene activation.
CDN Nutritional Genomics & Precision 2
Which single nucleotide polymorphism (SNP) in the MTHFR gene is most commonly associated with reduced folate metabolism?