Quantitative assessment of skin, hair, and iris variation in a diverse sample of individuals and associated genetic variation

Bibliographic Data

ID8319836
AuthorsHeather L Norton (0000-0001-7844-9156, Department of Anthropology University of Cincinnati Cincinnati OH 45238, corresponding author), Melissa Edwards (0000-0002-3627-7314, Department of Anthropology University of Toronto Mississauga Toronto ON, Canada), S Krithika (Department of Anthropology University of Toronto Mississauga Toronto ON, Canada), Monique Johnson (Department of Anthropology University of Toronto Mississauga Toronto ON, Canada), Elizabeth A Werren (0000-0002-0151-2564, Department of Anthropology University of Cincinnati Cincinnati OH 45238), Esteban J Parra (0000-0002-2057-8577, Department of Anthropology University of Toronto Mississauga Toronto ON, Canada)
Year2016
Volume160
Issue4
Pages570-581
Publication date2016-08-01
Peer ReviewedYes
Open AccessYes
TypeARTICLE
VenueAmerican Journal of Physical Anthropology (JOURNAL)
Journal identifiersISSN: 0002-9483 • E-ISSN: 1096-8644
PublisherWiley (PUBLISHER • GB)
DOI10.1002/ajpa.22861
PMID27435525
OpenAlexW2150828388
LanguageEN
Citations received7
References cited62

OBJECTIVES: The main goals of this study are to 1) quantitatively measure skin, hair, and iris pigmentation in a diverse sample of individuals, 2) describe variation within and between these samples, and 3) demonstrate how quantitative measures can facilitate genotype-phenotype association tests. MATERIALS AND METHODS: We quantitatively characterize skin, hair, and iris pigmentation using the Melanin (M) Index (skin) and CIELab values (hair) in 1,450 individuals who self-identify as African American, East Asian, European, Hispanic, or South Asian. We also quantify iris pigmentation in a subset of these individuals using CIELab values from high-resolution iris photographs. We compare mean skin M index and hair and iris CIELab values among populations using ANOVA and MANOVA respectively and test for genotype-phenotype associations in the European sample. RESULTS: All five populations are significantly different for skin (P <2 × 10(-16) ) and hair color (P <2 × 10(-16) ). Our quantitative analysis of iris and hair pigmentation reinforces the continuous, rather than discrete, nature of these traits. We confirm the association of three loci (rs16891982, rs12203592, and rs12913832) with skin pigmentation and four loci (rs12913832, rs12203592, rs12896399, and rs16891982) with hair pigmentation. Interestingly, the derived rs12203592 T allele located within the IRF4 gene is associated with lighter skin but darker hair color. DISCUSSION: The quantitative methods used here provide a fine-scale assessment of pigmentation phenotype and facilitate genotype-phenotype associations, even with relatively small sample sizes. This represents an important expansion of current investigations into pigmentation phenotype and associated genetic variation by including non-European and admixed populations. Am J Phys Anthropol 160:570-581, 2016. © 2015 Wiley Periodicals, Inc

Allele · Biology · Eye color · Gene · Genetic variation · Genotype · IRIS (biosensor) · Phenotype · Skin color · Forensic and Genetic Research · Genetics · melanin and skin pigmentation · Race, Genetics, and Society

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