rs3211883 — CD36

CD36 — Fat Sensor, Scavenger Receptor, and Metabolic Gatekeeper

CD36¹¹ CD36
CD36 molecule (also known as fatty acid translocase, FAT, or glycoprotein IV); a multifunctional class B scavenger receptor expressed on platelets, macrophages, adipocytes, enterocytes, skeletal muscle, and taste receptor cells performs a striking number of jobs simultaneously: it transports long-chain fatty acids across cell membranes, senses dietary fat on the tongue and in the gut, mediates uptake of oxidized LDL into macrophages (a key step in atherosclerotic plaque formation), and coordinates chylomicron assembly in intestinal epithelial cells. The rs3211883 variant sits deep in an intron of the CD36 gene on chromosome 7 and, while it does not directly change the protein sequence, it tags a haplotype that appears to modulate CD36 expression levels — with downstream consequences for fat handling and body composition.

The Mechanism

As an intronic variant²² intronic variant
A DNA change located within a non-coding intron; intronic variants typically act by altering regulatory elements, splice enhancers, or gene expression rather than changing the amino acid sequence of the protein, rs3211883 does not directly alter the CD36 protein. Instead, it marks a haplotype block that correlates with differences in CD36 surface expression on platelets — a finding documented in genome-wide association studies of CD36 expression quantitative trait loci. Lower CD36 expression in intestinal enterocytes reduces the protein's ability to coordinate chylomicron³³ chylomicron
Chylomicrons are large lipid-transporting particles assembled in intestinal cells after a fatty meal; they shuttle dietary fat from the gut into the lymphatic system and then into the bloodstream assembly from dietary fatty acids, potentially altering the rate at which long-chain fats move from the gut into circulation. Altered CD36 expression also affects fat taste perception — individuals with lower CD36 expression show reduced oral sensitivity to oleic acid, which may blunt the satiety signals normally triggered by fat consumption and contribute to higher overall energy intake.

The Evidence

The most direct evidence for rs3211883 comes from a study of 646 European adolescents by Bokor et al. (2010)⁴⁴ Bokor et al. (2010)
Bokor S et al. Single-nucleotide polymorphism of CD36 locus and obesity in European adolescents. Obesity (Silver Spring), 2010, which found that carriers of the minor A allele had a significantly elevated odds ratio for obesity of 1.73 (95% CI 1.16–2.59, P=0.007). The association extended to higher BMI and body fat percentage in the validation cohort. A haplotype carrying the minor alleles of four CD36 SNPs — including rs3211883 — was associated with even higher obesity risk (OR 2.28, P=0.0008).

However, a subsequent meta-analysis by Choquet et al. (2011)⁵⁵ meta-analysis by Choquet et al. (2011)
Choquet H et al. Lack of association of CD36 SNPs with early onset obesity: a meta-analysis in 9,973 European subjects. Obesity (Silver Spring), 2011 combining data from 9,973 European subjects found no significant association of rs3211883 with obesity risk (P=0.66). This discrepancy is common in early-generation genetic association studies and reflects the modest effect size of individual intronic variants whose primary role is haplotype-tagging rather than direct functional change.

Stronger evidence emerged from Heni et al. (2011)⁶⁶ Heni et al. (2011)
Heni M et al. Variants in the CD36 gene locus determine whole-body adiposity, but have no independent effect on insulin sensitivity. Obesity, 2011, who genotyped six CD36 SNPs tagging all common variation in the gene in 1,790 Europeans at risk for type 2 diabetes. rs3211883 and rs3211908 were among the variants that significantly associated with waist circumference after Bonferroni correction (P<0.0042). Critically, no independent effect on insulin sensitivity was detected — suggesting the variant affects metabolic risk primarily through its influence on fat distribution rather than direct insulin signaling.

On the molecular side, genome-wide association studies of platelet CD36 surface expression have linked rs3211883 to measured CD36 protein levels (P=0.000298, β=0.69), providing a plausible intermediate mechanism: the variant's haplotype influences how much CD36 protein is produced, which then affects both platelet activation responses to oxidized LDL and intestinal fat handling.

A population-specific finding came from a Japanese cohort study⁷⁷ Japanese cohort study
Kondo N et al. Positive association of common variants in CD36 with neovascular age-related macular degeneration. Aging (Albany NY), 2009 of 109 neovascular AMD cases and 182 controls, where the A allele was actually protective against AMD (OR 0.50, P=2.09×10⁻⁴ after Bonferroni correction). This underscores that the allele's effects are context- and tissue-specific: the same variant that tags increased adiposity risk in Western European populations may have neutral or even protective effects in retinal vasculature in East Asian populations.

Practical Actions

The A allele's primary documented effect is on body fat distribution — specifically waist circumference and overall adiposity. Since CD36 regulates the gut's fat-sensing machinery, individuals with the A allele may benefit from dietary strategies that compensate for altered fat absorption signaling. The protein's established role in long-chain saturated fatty acid transport means that dietary fat composition — not just quantity — is relevant. High saturated fat loads may overwhelm altered CD36 signaling in ways that unsaturated fats do not.

Given the A allele's association with higher platelet CD36 expression in some studies and CD36's role in oxidized LDL uptake by macrophages, monitoring of cardiovascular lipid markers is reasonable for A allele carriers, particularly if other cardiovascular risk factors are present.

Interactions

rs3211883 is in partial linkage disequilibrium with other functional CD36 variants, most notably rs1761667 (associated with oral fat perception and CD36 expression) and rs1527483 (linked to fat taste preferences and triglyceride levels). Individuals carrying the A allele at rs3211883 alongside the A allele at rs1761667 may have compounding impairments in dietary fat sensing that amplify the risk of excess energy intake from high-fat foods. The rs3173798 variant, which sits nearby in the CD36 gene and showed association with AMD in the same Japanese cohort, is in strong LD with rs3211883 in East Asian populations — indicating these two SNPs likely tag the same underlying haplotype in that ancestry group.