The idea to explore
A reading guide to Dr. Purser’s chapter listing genetic variants discussed in relation to elevated homocysteine.
Follow the connections
The chapter connects folate handling, methylation, vitamin B12 recycling and sulfur-amino-acid metabolism. Use the gene names as routes into the gene reference library. The exact variant identifier and clinical interpretation matter more than a gene name or a red-colored result on an app.
Read the variant, not just the gene name
A gene is a set of instructions; a variant is a particular difference in those instructions. Different variants in the same gene can have very different significance. “Homozygous” describes having the same variant in both copies at a location; it is not a severity score. MTHFR C677T and A1298C therefore need to be read as specific findings in context, not as proof that all of methylation is blocked. The source’s gene list is a map of topics to investigate.
Reading with perspective
The source’s gene lists are teaching material, not a validated diagnostic panel. A common variant, even when present in both copies, does not by itself prove a fixed homocysteine elevation, cytokine abnormality or need for a supplement.
A question for your next conversation
Which exact variant was measured, and what is its clinical classification?
BUILD YOUR UNDERSTANDING
A few concepts, made clearer.
CBS
CBS is the gene symbol used for Cystathionine Beta-Synthase. This page connects its terminology with the topics in the Purser Wellness teaching library.
Read the full referenceGGH
GGH is the gene symbol used for Gamma-Glutamyl Hydrolase. This page connects its terminology with the topics in the Purser Wellness teaching library.
Read the full referenceMTHFR
Makes an enzyme that helps produce a form of folate used in the processing of homocysteine. Common variants are different from rare variants that cause severe MTHFR deficiency.
Read the full referenceMTR
Makes the methionine synthase enzyme, which uses vitamin B12 in the conversion of homocysteine to methionine.
Read the full referenceLET YOUR CURIOSITY LEAD
One idea opens another.
Choose a subject to find the related teaching across videos, articles, courses and references.
About this reading
Chapter 3: Twenty-Two Genetic SNPs Associated With Hyperhomocysteinemia
Homocysteine chapter collection supplied by Purser Wellness.
This page combines an editorial adaptation with introductory explanations and links to the reference library, prepared September 17, 2026. Search covers the published explanations and topic names, not the full original document. Original files, patient examples and individualized protocols are not published here. This adaptation has not received an independent clinical review.
