rs7495174

neutralMag 4.5

This is a intron variant variant in the OCA2 gene.

Key Literature Trait Associations

Eye Color (Green/Hazel vs Brown)

This intronic variant in OCA2 modifies iris color, particularly the green/hazel vs brown distinction that rs12913832 in HERC2 cannot fully explain. The A allele forms part of a three-SNP OCA2 haplotype found in ~90% of blue/green eyes in Europeans, while the G allele is enriched in brown-eyed individuals. Together with rs12913832, this provides much of the predictive power used by forensic eye-color tools.

Hair color

rs7495174 in OCA2 is associated with hair color variation in genome-wide association analyses. A GWAS of 7,091 Dutch twins found this variant reaching nominal significance across multiple hair color contrasts (brown vs non-brown, light vs dark), with ORs of approximately 2.8–3.6 and p-values near 10⁻⁶ to 10⁻⁷. The association is consistent with OCA2's role in melanin synthesis affecting both eye and hair pigmentation, though the effect on hair color is somewhat less pronounced and less replicated than its effect on eye color.

Allele G
OR 3.11
p 3.0e-6
N 7,091
Small GWAS
European (Dutch)

ClinVar annotation

no_classification_for_the_single_variant
2 publications
View on ClinVar →

Research that mentions this SNP (8)

Variants at chromosome 20 (ASIP locus) and melanoma risk
AssociationN=1,033Maccioni L. et al.(2013)· International Journal of Cancer

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.

Traits studied:Pigmentation phenotypeProstate cancerSerum PSA levelsSun sensitivity
A global view of the OCA2-HERC2 region and pigmentation
AssociationN=3,432Michael P. Donnelly et al.(2012)· Human Genetics

This global population study of 3,432 individuals from 73 populations examined 21 SNPs in the OCA2-HERC2 region associated with eye and skin pigmentation. Blue-eye associated haplotypes (BEH1, BEH2, BEH3) were found at high frequencies in Europe, with BEH2 showing the strongest signal of selection. The East Asian-specific missense SNP rs1800414 (His615Arg) was associated with lighter skin pigmentation and showed strong evidence of positive selection in East Asian populations.

Traits studied:Eye pigmentation (blue eyes)Eye pigmentation (green/hazel eyes)Skin pigmentation (light skin)
Association of TGFβ1 and clinical factors with scar outcome following melanoma excision
AssociationN=202Ward SV et al.(2012)· Archives of Dermatological Research

Genetic association study of 202 melanoma patients examining SNPs in 24 candidate genes related to pigmentation and wound healing in relation to scar outcome. SNP rs8110090 in TGFβ1 was significantly associated with poorer scar outcomes (p=0.0002). Clinical factors including younger age, shorter time since surgery, and presence of infection or eczema were also associated with worse scarring.

Traits studied:Scar heightScar outcome following melanoma excisionScar vascularityWound healing
Model-based prediction of human hair color using DNA variants
AssociationN=385Wojciech Branicki et al.(2011)· Human Genetics

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).

Traits studied:Auburn hairBlack hairBlond hairBlond-red hairBrown hairDark-blond hairHair colorRed hair
Genotyping of five single nucleotide polymorphisms in the OCA2 and HERC2 genes associated with blue‐brown eye color in the Japanese population
AssociationN=523Reiko Iida et al.(2009)· Cell Biochemistry and Function

This study examined genotype and haplotype frequencies of five SNPs in the OCA2 and HERC2 genes (rs7495174, rs4778241, rs4778138, rs12913832, rs1129038) that are associated with blue-brown eye color variation in a Japanese population of 523 brown-eyed individuals. Significant differences in genotype and haplotype distributions were found compared to African and European populations, with the A-GAG haplotype being most frequent in Japanese (0.568) versus low in Europeans (0.167), and rs12913832 and rs1129038 being mono-allelic in the Japanese population.

Traits studied:Blue-brown eye colorBrown eye colorEye color
Variants of theMATP/SLC45A2gene are protective for melanoma in the French population
AssociationN=362Mickaël Guedj et al.(2008)· Human Mutation

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.

Traits studied:Atypical nevi countFamilial Atypical Multiple-Mole and Melanoma (FAMMM) syndromeHair color (red hair phenotype)Malignant melanomaNevus count (moles)Quantitative skin color/pigmentationSkin cancer susceptibilitySkin pigmentation (arm)Skin pigmentation (buttock)
Blue eye color in humans may be caused by a perfectly associated founder mutation in a regulatory element located within the HERC2 gene inhibiting OCA2 expression.
AssociationN=200Eiberg H et al.(2008)· Human genetics

This study identified a founder mutation in HERC2 intron 86 (rs12913832) that is perfectly associated with blue eye color. Through linkage analysis of a large Danish family and association studies in 155 blue-eyed and 45 brown-eyed individuals, the researchers mapped the blue eye color locus to a 166 Kbp region and demonstrated that rs12913832 (G allele) and rs1129038 (A allele) are perfectly associated with blue eyes (P = 6.12e-46). Functional studies showed this regulatory element significantly reduces OCA2 promoter activity through differential binding of transcription factors.

Traits studied:Blue eye colorBrown eye colorEye color variationHair color
MC1R common variants, CDKN2A and their association with melanoma and breast cancer risk
AssociationN=362Tadeusz Dȩbniak et al.(2006)· International Journal of Cancer

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.

Traits studied:Atypical nevi countFamilial atypical multiple-mole and melanoma (FAMMM) syndromeMelanoma riskNevi countSkin color (quantitative)

Gene information from NCBI Gene. Variant classifications from ClinVar.

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