PEMT rs7944135: Modulating Choline Needs and Fatty Liver Risk
The rs7944135 single-nucleotide polymorphism is a common regulatory variant located within the PEMT gene, which encodes the enzyme phosphatidylethanolamine N-methyltransferase. In humans, PEMT facilitates the de novo biosynthesis of choline-derived phosphatidylcholine in the liver. Research indicates that specific alleles at rs7944135 may alter PEMT expression, subtly modulating an individual's susceptibility to dietary choline deficiency and hepatic fat accumulation.
What each genotype means
Typical baseline choline synthesis
You carry two copies of the common T allele at rs7944135, which is associated with standard endogenous biosynthesis of phosphatidylcholine via the PEMT pathway. In dietary deficiency studies, individuals with this genotype generally demonstrated lower susceptibility to developing choline deficiency-induced hepatic steatosis or muscle damage compared to C allele carriers. However, evidence connecting this specific regulatory variant directly to clinical outcomes remains limited.
Carried by roughly 45% to 55% of individuals of European ancestry, representing the most common genotype in most populations.
Intermediate choline deficiency susceptibility
You have one copy of the C minor allele and one copy of the T allele in the PEMT promoter region. Research suggests intermediate de novo synthesis of phosphatidylcholine, which may slightly increase your reliance on dietary choline intake during times of nutritional restriction. Because the published nutrigenomic evidence for rs7944135 is limited and observational, standard recommended dietary intakes for choline are generally sufficient unless advised otherwise by a nutritionist or physician.
Carried by approximately 35% to 45% of individuals of European ancestry.
Elevated dietary choline sensitivity
You carry two copies of the C minor allele, which has been linked in preliminary human feeding studies to lower baseline PEMT expression and reduced de novo choline synthesis. When deprived of adequate dietary choline, individuals with homozygous C genotypes were more prone to developing subclinical liver dysfunction or elevated liver enzymes compared to non-carriers. This evidence is classified as limited, and this finding represents a dietary susceptibility rather than an inherited metabolic disorder.
Found in roughly 6% to 12% of individuals in European and nearby ancestral groups.
What Is rs7944135 and Where Is It Located?
The single-nucleotide polymorphism rs7944135 is a genetic variation situated on human chromosome 17 within the non-coding regulatory architecture of the phosphatidylethanolamine N-methyltransferase (PEMT) gene. Rather than directly substituting an amino acid in the encoded protein structure, regulatory polymorphisms like rs7944135 typically influence transcriptional activity, modifying the rate or efficiency with which the PEMT gene is transcribed into messenger RNA. In human populations, the primary alleles characterized at this locus on the forward strand are the T (major/reference) allele and the C (minor/alternative) allele. Because non-coding regulatory variations often fine-tune enzyme expression rather than abolishing protein function entirely, their biological consequences are typically continuous and heavily contingent upon environmental exposures—especially an individual's habitual nutritional intake.
The Biological Role of the PEMT Gene
The PEMT gene encodes an integral membrane enzyme found predominantly on the endoplasmic reticulum and mitochondria-associated membranes of hepatocytes. The PEMT pathway serves as the body's primary endogenous route for synthesizing phosphatidylcholine, a critical phospholipid required for cellular membrane integrity, bile excretion, and the packaging and export of very-low-density lipoproteins (VLDL). While phosphatidylcholine can also be synthesized through the CDP-choline (Kennedy) pathway using preformed choline acquired through diet, PEMT allows the liver to generate phosphatidylcholine de novo by sequentially methylating phosphatidylethanolamine using S-adenosylmethionine (SAM) as a methyl donor. When PEMT activity is diminished, hepatocytes struggle to assemble VLDL particles, trapping triglycerides within the liver and making the individual far more reliant on dietary choline sources to prevent hepatic steatosis.
Scientific Research and Evidence Strength
Published nutritional genomics research has repeatedly investigated polymorphisms within PEMT for their roles in modulating dietary choline requirements and nonalcoholic fatty liver disease (NAFLD) risk. Controlled feeding studies show that individuals carrying lower-expression PEMT alleles are significantly more prone to developing hepatic steatosis and elevated liver transaminases when placed on experimental choline-depleted diets. However, the evidence specifically surrounding rs7944135 remains categorized as limited to moderate. Many associations are confounded by linkage disequilibrium with other well-studied PEMT variants, such as the missense variant rs7946 (V175M) or promoter polymorphisms like rs12325817. Furthermore, biological sex and hormonal status significantly modulate these effects: estrogen strongly stimulates PEMT promoter activity, meaning premenopausal women often retain adequate endogenous synthesis even when carrying low-expression genetic variants, whereas men and postmenopausal women exhibit higher vulnerability to choline deficiency.
Population Distribution and Ancestral Patterns
Allele frequencies for rs7944135 vary widely across diverse geographic ancestries. In European populations, the minor C allele occurs at a frequency between 0.25 and 0.35, resulting in roughly 40% to 50% of European individuals carrying at least one copy of the variant allele (heterozygous CT or homozygous CC). In African and East Asian populations, allele frequencies deviate, reflecting divergent ancestral patterns in lipid and one-carbon metabolism. Because human diets historically varied extensively in available choline sources—such as animal liver, egg yolks, and organ meats—evolutionary selection pressures likely maintained considerable diversity across PEMT haplotypes. Public databases including gnomAD and dbSNP track these distribution variances across worldwide reference panels.
Practical Implications and Clinical Perspective
A consumer finding their rs7944135 genotype must understand that genetic variants in PEMT are strictly probabilistic rather than diagnostic. Carrying one or two copies of the C allele does not imply a clinical diagnosis of fatty liver disease, nor does it guarantee organ dysfunction. Instead, it indicates a potential biological vulnerability under circumstances where dietary intake of choline, folate, or related methyl donors falls chronically below established adequate intakes. Readers should not self-prescribe high-dose choline supplements based purely on genotype data, as excessive intake carries adverse effects including gastrointestinal distress and elevation of trimethylamine N-oxide (TMAO). Anyone with concerns about liver health, lipid metabolism, or dietary adequacy should review their results and nutritional habits in collaboration with a registered dietitian or physician.
How common is this variant?
The minor C allele at rs7944135 is observed at an estimated frequency of approximately 0.25 to 0.35 in European populations, with intermediate frequencies observed across other global ancestral groups in genomic databases such as gnomAD.
Frequently asked questions
Does having the rs7944135 C allele mean I will get fatty liver disease?
No. The rs7944135 variant represents a statistical susceptibility factor rather than a deterministic cause of disease. Nonalcoholic fatty liver disease develops due to a multifaceted combination of total caloric intake, metabolic health, physical activity, alcohol consumption, and overall dietary quality.
Can I test my liver function to see if my PEMT variant is having an effect?
Routine clinical blood panels—including liver transaminases such as ALT and AST—along with abdominal imaging can evaluate liver health. If you are concerned about your genetic results or hepatic function, a physician can order and interpret appropriate diagnostic tests.
Should I take high-dose choline supplements if I have the CC genotype?
You should not initiate high-dose choline supplementation without clinical guidance. Most health professionals recommend meeting the standard Adequate Intake (AI) for choline through nutrient-dense whole foods like eggs, fish, legumes, and poultry before considering dietary supplements.
Why does biological sex influence how PEMT variants behave?
The PEMT gene contains estrogen-response elements in its promoter region, allowing circulating estrogens to upregulate enzyme expression. Because of this hormonal stimulation, premenopausal women often maintain higher baseline PEMT activity than men or postmenopausal women, buffering them against the negative impacts of low-expression variants.
Sources & further reading
Educational information only, last refreshed 9/13/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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Functional regulatory promoter SNP in phosphatidylethanolamine N-methyltransferase impairing estrogen-induced de novo choline synthesis and raising dietary choline needs.
PEMT variant affects choline metabolism; carriers may need more dietary choline from eggs, meat, and fish.