COMPENDIUM ON FUNCTIONAL MEDICINE - Flipbook - Page 205
● Ensembl: A genome browser for vertebrate genomes that
supports research in comparative genomics and sequence
variation.
● SNP Nexus: A comprehensive annotation tool for SNPs.
● GenomeBrowse: Free genomic data visualization software for
academics and students.
Important SNPs and Their Meanings
MTHFR (Methylenetetrahydrofolate Reductase) - In Depth
Function: MTHFR is a key enzyme in folate metabolism and the
methylation cycle, which is crucial for numerous bodily functions
including DNA synthesis, neurotransmitter production, and
detoxification [17].
Common Variants:
C677T (rs1801133)
This SNP causes a substitution of cytosine (C) with thymine (T) at
position 677, resulting in an alanine to valine change in the
protein. This creates a thermolabile MTHFR enzyme with reduced
activity - approximately 30-40% reduction in heterozygotes and up
to 70% reduction in homozygotes. It is associated with increased
homocysteine levels, cardiovascular issues, and potentially
increased risk of depression and neurological conditions [18].
A1298C (rs1801131)
This SNP results in a substitution of adenine (A) with cytosine (C) at
position 1298, causing a glutamate to alanine change in the
protein. While it has a milder impact on enzyme function than
C677T, it can still affect methylation processes. When combined
with C677T, it may compound methylation issues [18].
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