Tag SNP for HLA-DRB5*01:01 on the DR15 susceptibility haplotype, physically near HLA-DRB5 in the MHC region and in near-complete LD with rs3135388; the DRB5*01:01 allele contributes independently to multiple sclerosis and narcolepsy risk by presenting myelin and viral peptides to autoreactive CD4+ T cells

Tag SNP proxy for GSTM1 gene deletion status — the most common pharmacogenomic variant worldwide, eliminating a Phase II detoxification enzyme that conjugates glutathione to environmental carcinogens

Near-complete loss-of-function CYP2B6 variant causing severely impaired metabolism of efavirenz, bupropion, methadone, and other CYP2B6 substrates

Common intronic variant near glucokinase that raises fasting glucose by impairing the pancreatic glucose-sensing threshold; each A allele adds ~0.062 mmol/L to fasting glucose and modestly reduces beta-cell function

Missense variant in glyoxalase 1 reducing enzyme activity, allowing methylglyoxal to accumulate — a GABA-A receptor modulator that influences anxiety and sleep quality

Intronic APOA2 tag SNP that captures the saturated fat-weight gain interaction — G allele carriers gain more weight on high saturated fat diets due to reduced APOA2-mediated satiety signaling

Intergenic variant near the SFRP5 adipokine locus; the A allele is strongly enriched in African ancestry (~19% MAF) and absent in East Asian populations, tagging a regulatory region that may influence SFRP5 expression — the anti-inflammatory adipokine that suppresses pro-inflammatory Wnt5a signaling in adipose tissue

Intronic variant in the CST complex component STN1/OBFC1 that influences telomere length; the C allele drives longer telomeres and elevated cancer risk while the A allele predisposes to shorter telomeres and accelerated cellular aging

Promoter polymorphism 589 bases upstream of the IL-4 transcription start site; the T allele enhances NFAT-1 binding, elevates IL-4 transcription, raises serum IgE, and amplifies Th2-skewed immune responses underlying allergic asthma, atopic dermatitis, and allergic rhinitis

Tag SNP for HLA-DRB1*15:01 (physically located near HLA-DRA), the strongest genetic risk factor for multiple sclerosis, with implications for vitamin D optimization and EBV immune control