Regulatory variant that reduces reduced folate carrier protein expression, impairing folate uptake into cells

Promoter variant ~1993 bp upstream of TBX21 (encoding the T-bet master transcription factor) that reduces TBX21 expression and blunts Th1-mediated immunity; the C allele is associated with altered Th1/Th2 balance, hypothyroidism susceptibility, and aspirin-induced asthma risk in Asian populations.

Intronic CYP2D6 variant tagging East Asian *10-lineage suballeles; the C allele co-segregates with reduced-function haplotypes affecting metabolism of ~25% of prescribed medications

Pathogenic PSEN1 missense mutation (His163Tyr) that impairs gamma-secretase processivity, elevating the Aβ42/Aβ40 ratio and causing autosomal dominant early-onset familial Alzheimer's disease with average onset around age 51.

Intronic GCKR enhancer variant that modulates FOXA2-driven GCKR expression in liver; the C allele reduces GCKR expression and weakens hepatic glucokinase braking, contributing to the glucose-triglyceride trade-off pattern characteristic of the GCKR locus — lower fasting glucose and insulin at the cost of elevated triglycerides and NAFLD susceptibility

Promoter variant controlling YKL-40 (chitinase 3-like 1) expression; the common C allele drives higher circulating YKL-40 levels and increased susceptibility to asthma and airway inflammation

Factor V Leiden - blood clotting disorder affecting thrombosis risk

Pathogenic PSEN1 missense variant at codon 278 that disrupts gamma-secretase substrate processing, shifts amyloid-beta production toward longer amyloidogenic species (Aβ42, Aβ43), and causes autosomal dominant early-onset familial Alzheimer's disease typically presenting between ages 40 and 55.

Main type 2 diabetes risk variant - strongly modulated by dietary fat

Intronic variant in RTEL1 (regulator of telomere elongation helicase 1) associated with atopic dermatitis risk; the A allele increases AD susceptibility through impaired telomere-dependent immune cell renewal