DAO structural variant near the catalytic domain affecting histamine degradation

Synonymous CYP2D6 variant that promotes exon 3 skipping, reducing functional enzyme expression by ~50% and affecting metabolism of ~25% of prescription drugs

5' UTR variant in RBP4 that influences expression of retinol binding protein 4, an adipokine associated with insulin resistance and type 2 diabetes susceptibility when elevated

Intronic CYP2J2 tag SNP; the C allele marks a haplotype associated with reduced epoxyeicosatrienoic acid (EET) production and increased myocardial infarction risk through impaired cardioprotective vasodilation

3' UTR and intronic IL23R variant disrupting Let-7e/Let-7f miRNA binding — the A allele elevates IL-23 receptor expression and is associated with ankylosing spondylitis, inflammatory bowel disease, and rheumatoid arthritis susceptibility; the C allele was independently associated with Graves' ophthalmopathy in a Caucasian cohort

Intronic EXT2 variant associated with a modest increase in type 2 diabetes susceptibility; the C allele impairs heparan sulfate-mediated insulin signaling in adipose tissue and pancreatic beta-cells.

Intronic regulatory variant in TBX21 that influences T-bet expression and Th1/Th2 immune balance; the minor T allele is associated with elevated regulatory T-cell markers and reduced early-childhood atopic dermatitis risk, while the common C allele is linked to lower CD4+CD25+ Treg frequency and higher susceptibility to atopic disease

An FTO intron-8 variant in the same haplotype block as rs1420318, with emerging associations with bone mineral density and alcohol dependence susceptibility; distinct from the primary intron-1 obesity cluster

Common variant in the 3' UTR of the DIO1 gene affecting thyroid hormone metabolism and T3/T4 ratio

Missense variant in the PARP1 catalytic domain that reduces enzymatic activity by ~40%, impairing DNA single-strand break repair and altering NAD+ consumption dynamics