PNPLA3 rs738409: What Your Genotype Means for Liver Health
The rs738409 variant in the PNPLA3 gene is a well-studied genetic marker associated with the accumulation of fat in the liver. It is considered a primary genetic risk factor for metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as NAFLD.
What each genotype means
Baseline liver risk profile
This genotype represents the most common form of the PNPLA3 gene, which is associated with normal triglyceride hydrolase activity in the liver. Individuals with this genotype do not carry the I148M risk variant and generally have a lower genetic predisposition to non-alcoholic fatty liver disease (NAFLD) compared to those with G alleles.
This is the most common genotype in many populations, though its frequency varies significantly by ancestry.
Intermediate liver risk profile
Carrying one copy of the G allele (also known as the I148M variant) is associated with reduced triglyceride hydrolase activity in the liver. Research indicates that individuals with this genotype are at an intermediate risk for developing fatty liver disease and related liver complications compared to those without the variant.
This genotype is common in the general population, with higher prevalence observed in Hispanic individuals.
Elevated liver risk profile
This genotype, where both copies of the gene carry the G allele (I148M), is strongly associated with significantly diminished triglyceride hydrolase activity. Research shows that individuals with this genotype face the highest genetic risk for developing non-alcoholic fatty liver disease (NAFLD), liver inflammation, and progression to cirrhosis.
This genotype is less common than the CC or CG genotypes in many populations, but it is notably more frequent in Hispanic populations.
Understanding the rs738409 Variant
The rs738409 variant is a single-nucleotide polymorphism (SNP) located within the PNPLA3 gene. In this specific location, a change occurs where the DNA base cytosine (C) is replaced by guanine (G). This genetic change results in a functional alteration in the protein produced by the gene, specifically substituting the amino acid isoleucine with methionine at position 148, commonly referred to as the I148M variant. Because this change occurs in the coding region of the gene, it alters the structure and function of the resulting protein, which plays a critical role in how liver cells manage fats. Researchers have identified this variant through genome-wide association studies as a significant factor influencing hepatic lipid content.
The Role of the PNPLA3 Gene
The PNPLA3 gene encodes a protein known as patatin-like phospholipase domain-containing protein 3. This protein is primarily expressed in the liver and is involved in the regulation of lipid droplets within hepatocytes, the main functional cells of the liver. Under normal conditions, the PNPLA3 protein helps in the remodeling and breakdown of triglycerides. However, the I148M mutation caused by the rs738409 variant impairs this process. Research indicates that the mutant protein has a reduced ability to hydrolyze triglycerides, leading to the accumulation of fat within liver cells. This disruption in lipid metabolism is a key mechanism by which the variant contributes to the development of steatosis, or fatty liver, and potentially more severe forms of liver disease.
Research and Clinical Associations
The association between the rs738409 G allele and liver health is considered strong across multiple scientific studies. Carriers of the G allele, particularly those with the GG genotype, show a higher susceptibility to metabolic dysfunction-associated steatotic liver disease (MASLD). Evidence suggests that this variant not only influences the amount of fat stored in the liver but may also contribute to the progression of liver inflammation, fibrosis, and in some cases, hepatocellular carcinoma. These effects are often more pronounced in individuals with other risk factors, such as obesity or high body mass index. While the link is robust, it is important to note that the presence of this variant does not guarantee the development of liver disease, as environmental factors and lifestyle choices play a significant role in overall liver health.
What This Information Means for You
Knowing your genotype for rs738409 provides insight into your genetic predisposition regarding liver fat metabolism. However, it is essential to understand that this is only one piece of a complex puzzle. Genetic markers are not diagnostic tools; they indicate statistical risk rather than certainty. If you are concerned about your liver health, the most effective approach is to consult with a healthcare professional who can evaluate your overall health profile, including blood tests, imaging, and lifestyle factors. There is no specific medication or treatment based solely on this genotype. Instead, focus on evidence-based lifestyle habits that support liver health, such as maintaining a balanced diet and regular physical activity. Always discuss any concerns about your health or genetic results with a qualified clinician.
How common is this variant?
The rs738409 variant is common globally, though its frequency varies by ancestry. It is notably more prevalent in Hispanic populations compared to other groups.
Frequently asked questions
Does having the GG genotype mean I will get liver disease?
No, having the GG genotype does not mean you will develop liver disease. It indicates a higher genetic susceptibility, but environmental factors like diet, exercise, and alcohol consumption are major contributors to liver health.
Is there a specific diet for people with the PNPLA3 variant?
There is no specific 'genotype-based' diet. Generally, health professionals recommend a balanced diet low in processed sugars and saturated fats to support liver health, regardless of your genetic makeup.
Should I get tested for the PNPLA3 rs738409 variant?
Genetic testing for this variant is not currently a standard clinical requirement for the general population. If you have concerns about your liver health, speak with your doctor about standard clinical screenings like liver enzyme tests.
Can I change my risk if I have the G allele?
While you cannot change your genetics, you can manage your overall risk through lifestyle modifications. Maintaining a healthy weight and avoiding excessive alcohol intake are effective ways to support liver function.
Sources & further reading
Educational information only, last refreshed 10/17/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs738409?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in PNPLA3
The p.Ile148Met variant in PNPLA3 is a major genetic determinant of hepatic fat content and NAFLD risk.
Intronic regulatory variant in linkage disequilibrium with I148M associated with hepatic fat fraction and ALT levels.
This variant is in high linkage disequilibrium with the I148M (rs738409) variant, which is a major genetic determinant of hepatic fat content and susceptibility to NAFLD.
The PNPLA3 S453I variant is a rare variant associated with hepatic lipid metabolism; note that the common risk variant for NAFLD is rs738409.
An intronic variation in linkage disequilibrium with the major PNPLA3 non-alcoholic fatty liver disease (NAFLD) locus that contributes to individual liver fat accumulation and fibrosis predisposition.
This variant is associated with increased risk of non-alcoholic fatty liver disease and liver fat accumulation.