rs1800562

This comprehensive review examines the genetic background of nonalcoholic fatty liver disease (NAFLD), focusing on variants identified by genome-wide association studies (GWAS) and candidate gene studies. The most significant GWAS-identified variants are PNPLA3 rs738409 (I148M), which strongly associates with increased liver steatosis, fibrosis severity, and HCC risk (12-fold increased risk for homozygous carriers), and TM6SF2 rs58542926 (E167K), which increases NASH progression but reduces cardiovascular risk. The review also discusses numerous candidate genes involved in lipid and glucose metabolism and liver injury mechanisms.

Transethnic genome-wide meta-analysis in 159,940 individuals identified 60 common genetic variants associated with HbA1c levels. Variants were classified as glycemic (19), erythrocytic (22), or unclassified (19) based on their biological mechanisms. Glycemic variants were associated with higher type 2 diabetes risk (OR=1.05 per allele, p=3×10⁻²⁹), while erythrocytic variants were not. The X-linked G6PD G202A variant showed a large effect in African Americans (0.81% HbA1c reduction per allele) but minimal effects in other ancestries, potentially causing 2% of African American T2D cases to remain undiagnosed when using HbA1c screening.

This association study examined HFE gene mutations in 786 NAFLD patients from the NASH Clinical Research Network. NAFLD patients with C282Y mutations (rs1800562) had lower median serum hepcidin levels (57 vs 65 ng/ml, p=0.01) and higher mean hepatocellular iron grades (0.59 vs 0.28, p<0.001) compared to wild-type subjects. H63D mutations (rs1799945) were associated with higher steatosis grades and NAFLD activity scores (OR≥1.4, p≤0.041) but not with iron deposition, while C282Y mutations were associated with less ballooning or NASH (OR≤0.62, p≤0.024).

Genetic association study in 23,439 Caucasians and 7,112 African Americans identified novel loci modulating hematological traits. G6PD rs1050828 (Val68Met) shows strong association with red blood cell count, hemoglobin, hematocrit, and mean corpuscular volume in African Americans (P < 2.0 × 10^−13), while TPM4 rs8109288 associates with platelet count in both Caucasians and African Americans (P = 3.0 × 10^−7). HBA2-HBA1 rs1211375 associates with red blood cell traits specifically in African Americans (P < 7 × 10^−8). Study replicated 36 previously reported associations and highlights ethnic differences in genetic architecture of blood traits.

Comprehensive review of genetic background in nonalcoholic fatty liver disease (NAFLD). The PNPLA3 I148M variant (rs738409 C>G) is identified as a major genetic player strongly associated with increased liver fat content, NASH development, fibrosis severity, and HCC risk. The TM6SF2 E167K variant (rs58542926) emerges as another key contributor to NAFLD pathogenesis and disease progression. Multiple additional GWAS-identified variants and candidate genes are reviewed for their roles in NAFLD susceptibility and progression.

A systematic review and meta-analysis of SNP associations with hepatocellular carcinoma (HCC) identified six SNPs in five genes with overall statistical significance. Two SNPs passed reliability criteria: rs1800562 (HFE, Cys282Tyr) with a recessive model OR of 5.20 (95% CI: 2.69-10.08) across 9 studies, and rs2279744 (MDM2) with an allele contrast OR of 1.57 (95% CI: 1.36-1.80) across 5 studies. Both were classified as having moderate epidemiological evidence by Venice guidelines.

This study replicates a previous finding of epistatic interaction between rs1049296 (P589S in TF) and rs1800562 (C282Y in HFE) as risk factors for Alzheimer's disease in a combined sample of 1,166 cases and 1,404 controls from three European and European American populations. The study found significant synergy between the two variants (synergy factor=2.71, p=0.0016 unadjusted; OR=2.4, p=0.002 adjusted for age and APOE ε4), with bi-carriers of minor alleles showing approximately 2.4-fold increased disease risk.

Case-control study of 117 childhood acute lymphoblastic leukemia cases and 414 newborn controls from South Wales investigating the HFE gene and neighboring histone genes. Identified rs807212 as a tagging SNP for the common HFE haplotype with a strong male-specific protective association (adjusted OR=0.27 for heterozygotes, p=0.009) that accounts for the previously reported C282Y risk association. Analysis of 24 SNPs spanning 52 kb in the HFE region revealed complex haplotype structure with male-specific genetic effects.