CDN Nutritional Genomics & Precision 3 — Questions and Answers
Question 1: A client carries the BCMO1 R267S polymorphism affecting beta-carotene conversion. The most appropriate precision nutrition recommendation is:
- Increase beta-carotene-rich foods only
- Supplement with pre-formed retinol (vitamin A) (Correct answer)
- Eliminate all carotenoid-rich foods
- Increase zinc intake to compensate
Correct answer: Supplement with pre-formed retinol (vitamin A)
BCMO1 R267S reduces beta-carotene to retinol conversion efficiency, so individuals may need pre-formed vitamin A rather than relying solely on provitamin A carotenoids.
Question 2: The lactase persistence allele (LCT -13910 C>T) enables continued lactase expression in adults due to its effect on:
- A coding mutation in the LCT gene
- An enhancer element regulating LCT transcription (Correct answer)
- Epigenetic methylation of the LCT promoter
- Alternative splicing of LCT mRNA
Correct answer: An enhancer element regulating LCT transcription
The C>T variant at position -13910 upstream of LCT creates a binding site for transcription factors that enhance lactase expression into adulthood.
Question 3: Which omics technology directly measures the complete set of proteins expressed by a cell or tissue?
- Transcriptomics
- Metabolomics
- Proteomics (Correct answer)
- Genomics
Correct answer: Proteomics
Proteomics characterizes the full complement of proteins expressed at a given time, capturing post-translational modifications that genomics and transcriptomics cannot detect.
Question 4: A variant in the FADS1 gene affects which dietary fatty acid conversion pathway?
- Conversion of ALA to EPA and DHA (Correct answer)
- Synthesis of cholesterol from acetyl-CoA
- Conversion of linoleic acid to arachidonic acid
- Beta-oxidation of long-chain fatty acids
Correct answer: Conversion of ALA to EPA and DHA
FADS1 encodes delta-5 desaturase, which is critical for converting ALA to longer-chain omega-3 fatty acids EPA and DHA.
Question 5: In precision nutrition, the primary clinical utility of measuring a client's metabolome is to:
- Predict future genetic mutations
- Identify real-time metabolic phenotype and nutrient status (Correct answer)
- Replace genetic testing entirely
- Determine macronutrient intake history
Correct answer: Identify real-time metabolic phenotype and nutrient status
Metabolomics captures the downstream functional output of genome-environment interactions, reflecting actual metabolic state and nutritional biomarker levels.
Question 6: Which dietary pattern has the strongest evidence for favorably modifying the epigenome in populations at cardiovascular risk?
- High-protein carnivore diet
- Mediterranean diet rich in polyphenols and olive oil (Correct answer)
- High-fat ketogenic diet
- Western diet high in processed foods
Correct answer: Mediterranean diet rich in polyphenols and olive oil
The Mediterranean diet provides polyphenols, folate, and omega-3 fatty acids that support beneficial DNA methylation and histone modification patterns.
Question 7: The concept of 'genetic buffering' in nutrigenomics suggests that:
- Genetic variants always override dietary interventions
- A healthy diet can reduce the phenotypic expression of risk alleles (Correct answer)
- Nutrient supplementation eliminates genetic disease risk
- Genetic testing is unnecessary for dietary planning
Correct answer: A healthy diet can reduce the phenotypic expression of risk alleles
Genetic buffering describes how optimal nutritional environments can attenuate the clinical expression of high-risk genotypes, consistent with gene-environment interaction models.
CDN Nutritional Genomics & Precision 3
A client carries the BCMO1 R267S polymorphism affecting beta-carotene conversion.
The most appropriate precision nutrition recommendation is: