CDN Nutritional Genomics & Precision 4

Question 1

A client with homozygous MTHFR C677T variant is best supported by which form of folate supplementation?

Accepted Answer

5-methyltetrahydrofolate (5-MTHF)

Answer

5-MTHF bypasses the impaired MTHFR enzyme and is directly usable for methylation reactions, unlike synthetic folic acid which requires conversion.

Question 2

Which gene variant is most clinically relevant when counseling a patient about vitamin D supplementation requirements?

Accepted Answer

VDR Fok1 polymorphism

Answer

VDR Fok1 (rs2228570) alters vitamin D receptor protein length and transcriptional activity, influencing individual responsiveness to vitamin D supplementation.

Question 3

The HFE gene C282Y homozygous variant is most associated with which nutritional disorder?

Accepted Answer

Hereditary hemochromatosis with iron overload

Answer

HFE C282Y homozygosity is the most common cause of hereditary hemochromatosis, leading to excessive intestinal iron absorption and organ iron deposition.

Question 4

In the context of nutrigenomics, 'gene expression profiling' using microarrays measures:

Accepted Answer

mRNA levels of thousands of genes simultaneously

Answer

Microarray technology hybridizes labeled cDNA to probe arrays to quantify the transcriptomic response to dietary interventions across thousands of genes.

Question 5

A client with the COMT Val158Met low-activity genotype (Met/Met) may have altered metabolism of which dietary compound?

Accepted Answer

Catechol-containing polyphenols such as quercetin and EGCG

Answer

COMT methylates and inactivates catechol-structured compounds; the Met/Met variant reduces this activity, prolonging the effects of catechol polyphenols and catecholamines.

(CDN) Certified Dietician Nutritionist Practice Test

(CDN) Certified Dietician Nutritionist Practice Test

CDN Nutritional Genomics & Precision 4