rs28777

This study examined associations between sun-sensitive pigmentary gene variants and serum PSA levels in 1033 older Australian men. Variants in SLC45A2 (rs28777: -19.6%, rs16891982: -17.3%) were associated with lower PSA levels in all men. Variants in MC1R (rs1805007) and ASIP (rs4911414) showed significant interactions with birth region, with higher PSA levels in ANZ-born men carrying the variants. Post-hoc analysis found increased testosterone in MC1R rs1805007 carriers and elevated dihydrotestosterone in ASIP rs1015362 carriers.

This study demonstrates that human hair color can be predicted from DNA variants with high accuracy using a multinomial logistic regression model. A subset of 13 genetic markers from 11 genes (MC1R, HERC2, IRF4, TYR, EXOC2, SLC45A2, TYRP1, OCA2, SLC24A4, KITLG, ASIP) predicted hair color categories in Polish Europeans with AUC values of 0.93 for red hair, 0.87 for black hair, 0.82 for brown hair, and 0.81 for blond hair. MC1R variants showed the strongest association with red hair (OR=12.64 for R variants, P=2.5×10⁻¹⁷), while rs12913832 in HERC2 was significantly associated with darker hair colors (OR=3.33 for black, P=4.3×10⁻⁶).

Genome-wide association studies and comparative genomics have identified major pigmentation loci (SLC24A5, SLC45A2, TYR, OCA2, MC1R, IRF4, TPCN2) showing evidence of strong natural selection in human populations. Light skin variants in Europeans and Asians underwent complete or near-complete selective sweeps, with SLC24A5 rs1426654 and SLC45A2 variants representing independent evolutionary mechanisms. Critical skin-lightening variants arose 11,000-30,000 years ago during human demographic expansion, driven by UV radiation exposure, vitamin D synthesis requirements, and possibly sexual selection.

A cross-sectional genetic association study examining 362 Danish individuals investigating relationships between pigmentation genes and quantitative skin color, nevus counts, and familial atypical multiple-mole and melanoma (FAMMM) syndrome. MC1R variants were significantly associated with lighter arm pigmentation (p < 0.001), indicating effects on tanning response rather than constitutive skin color. No significant associations with FAMMM or nevus counts remained significant after Bonferroni correction for multiple testing.

This Danish study of 246 healthy individuals and 116 at-risk melanoma patients investigated associations between 32 pigmentary SNPs and quantitative skin color, nevi count, and familial atypical multiple-mole and melanoma (FAMMM) syndrome. Individuals carrying two or more MC1R variants (including missense mutations p.TYR152* and frameshift p.Asn29Glnfs*14) had significantly lighter skin on the upper-inner arm (p<0.001) reflecting impaired tanning ability, but no associations were found with FAMMM syndrome, suggesting FAMMM genetics are distinct from pigmentation pathways.