1
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Association of TYR SNP rs1042602 with Melanoma Risk and Prognosis. LIFE (BASEL, SWITZERLAND) 2022; 12:life12122004. [PMID: 36556369 PMCID: PMC9785037 DOI: 10.3390/life12122004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/26/2022] [Accepted: 11/28/2022] [Indexed: 12/02/2022]
Abstract
Cutaneous melanoma is the most aggressive of skin tumors. In order to discover new biomarkers that could help us improve prognostic prediction in melanoma patients, we have searched for germline DNA variants associated with melanoma progression. Thus, after exome sequencing of a set of melanoma patients and healthy control individuals, we identified rs1042602, an SNP within TYR, as a good candidate. After genotyping rs1042602 in 1025 patients and 773 healthy donors, we found that the rs1042602-A allele was significantly associated with susceptibility to melanoma (CATT test: p = 0.0035). Interestingly, we also observed significant differences between patients with good and bad prognosis (5 years of follow-up) (n = 664) (CATT test for all samples p = 0.0384 and for men alone p = 0.0054). Disease-free-survival (DFS) analyses also showed that patients with the A allele had shorter DFS periods. In men, the association remained significant even in a multivariate Cox Proportional-hazards model, which was adjusted for age at diagnosis, Breslow thickness, ulceration and melanoma subtype (HR 0.4; 95% confidence interval (CI) 0.20-0.83; p = 0.0139). Based on our results, we propose that rs1042602-A is a risk allele for melanoma, which also seems to be responsible for a poorer prognosis of the disease, particularly in men.
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2
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Dabas P, Jain S, Khajuria H, Nayak BP. Forensic DNA phenotyping: Inferring phenotypic traits from crime scene DNA. J Forensic Leg Med 2022; 88:102351. [DOI: 10.1016/j.jflm.2022.102351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 03/01/2022] [Accepted: 04/04/2022] [Indexed: 10/18/2022]
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3
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Jonnalagadda M, Bharti N, Kasibhatla SM, Wagh MA, Joshi R, Ozarkar S, Ashma R. MC1R diversity and its role in skin pigmentation variation in West Maharashtra, India. Am J Hum Biol 2022; 34:e23734. [PMID: 35188998 DOI: 10.1002/ajhb.23734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 02/02/2022] [Accepted: 02/08/2022] [Indexed: 01/05/2023] Open
Abstract
OBJECTIVES MC1R polymorphisms have been reported to be under a selective constraint in populations inhabiting high UVR regions such as Africans; however, these patterns are not consistent. Here we analyze the MC1R gene in West Maharashtra, India to see if sequence diversity corresponds to their diverse pigmentary profiles and if MC1R is constrained in dark skinned tribal as compared to lighter skinned caste populations. METHODS A 2648 bp region of this gene was sequenced in 102 individuals and the data was compared for π, ϴ diversity indices. Tajima's D was assessed for signatures of purifying selection and MC1R variants were associated with MI measures using the additive, dominant, and recessive models. Pairwise FST was tested among study populations and between study populations and 1000 Genomes regional samples. RESULTS MC1R diversity was not uniquely patterned among castes and tribes. Non-synonymous variants rs2228479A, rs1805007_T, and rs885479_A showed low variability in these populations. Selection tests did not indicate any constraint on MC1R and pairwise FST were also low among the study populations (-0.0163 to 0.06112). The SNP rs3212359 was significantly associated with MI measures when tested using different association models. CONCLUSIONS We do not find evidence of a selective constraint on MC1R. The presence of a large number of unique haplotypes and low FST values at this locus suggests that MC1R polymorphisms may not be influencing pigmentation variation among castes and tribes in this region. Observed associations between rs3212359 and MI measures need to be validated through studies on larger samples and in-vitro functional studies.
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Affiliation(s)
- Manjari Jonnalagadda
- Symbiosis School for Liberal Arts, Symbiosis International (Deemed University), Pune, India
| | - Neeraj Bharti
- HPC-MBA Group, C-DAC Innovation Park, Centre for Development of Advanced Computing, Pune, India
| | | | - Mayur A Wagh
- Symbiosis School for Liberal Arts, Symbiosis International (Deemed University), Pune, India
| | - Rajendra Joshi
- HPC-MBA Group, C-DAC Innovation Park, Centre for Development of Advanced Computing, Pune, India
| | - Shantanu Ozarkar
- Department of Anthropology, Savitribai Phule Pune University, Pune, India
| | - Richa Ashma
- Department of Zoology, Savitribai Phule Pune University, Pune, India
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4
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Wang Y. Association of pigmentation related-genes polymorphisms and geographic environmental variables in the Chinese population. Hereditas 2021; 158:24. [PMID: 34238381 PMCID: PMC8268332 DOI: 10.1186/s41065-021-00189-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 06/09/2021] [Indexed: 11/10/2022] Open
Abstract
Background Human skin color is highly heritable and one of the most variable phenotypic traits. However, the genetic causes and environmental selective pressures underlying this phenotypic variation have remained largely unknown. To investigate whether the pigmentation related-genes polymorphisms are associated with the geographic environmental variables. We selected randomly 795 healthy individuals from eight ethnic groups in nine provinces in China. Six single nucleotide polymorphisms (SNPs) of SLC45A2 and TYR were genotyped using Agena MassARRAY. The Chi-square test and Spearman correlation analysis were used to compare the frequency distribution of genotypes among different ethnic groups and evaluate the relationship between SNP genetic diversity and environmental variables, respectively. Results The results indicated that rs28777 and rs183671 (SLC45A2) and rs1042602 (TYR) genotype frequency distributions were significantly different between the Xinjiang-Uighur and other ethnic groups (P < 0.05). Spearman correlation analysis found that rs28777-A (r = − 0.090, P = 0.011), rs183671-G (r = − 0.105, P = 0.003), rs1042602-A (r = − 0.108, P = 0.002), rs1126809-A (r = − 0.151, P < 0.001) allele frequencies were negatively correlated with the longitude; rs183671-G (r = 0.151), rs1042602-A (r = 0.157) and rs1126809-A (r = 0.138) allele frequencies were positively associated with the latitude (P < 0.001); rs183671-G (r = 0.116, P = 0.001), rs1042602-A (r = 0.105, P = 0.003) and rs1126809-A (r = 0.070, P = 0.048) allele frequencies were positively correlated with the sunshine hours; rs183671-G (r = − 0.076, P = 0.033), rs1042602-A (r = − 0.079, P = 0.027) and rs1126809-A (r = − 0.076, P = 0.031) were negatively correlated with the annual average temperature. Conclusions Our results confirmed the idea that environmental factors have been an important selective pressure upon pigmentation related gene polymorphisms. Supplementary Information The online version contains supplementary material available at 10.1186/s41065-021-00189-7.
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Affiliation(s)
- Yuxin Wang
- Queen Mary School, Nanchang University, 461 Bayi Road, Nanchang, 330006, Jiangxi, China.
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5
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Norton HL. The color of normal: How a Eurocentric focus erases pigmentation complexity. Am J Hum Biol 2020; 33:e23554. [PMID: 33337560 DOI: 10.1002/ajhb.23554] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 11/06/2022] Open
Abstract
OBJECTIVES Skin pigmentation is both a highly variable and highly visible human phenotypic trait. Investigations into the biology and origins of this variation have been the focus of research in the fields of dermatology, anthropology, and forensic science, among others. This manuscript explores how much of what we know about the biology, genetics, and evolutionary origins of pigmentation has been strongly influenced by investigations and applications that focus on lighter skin. METHODS I reviewed literature from the fields of dermatology, anthropology and evolutionary genetics, and forensic science to assess how perceptions of lighter skin as the "normal" state in humans can shape the ways that knowledge is gathered and applied in these fields. RESULTS This normalization of lighter skin has impacted common tools used in dermatology and shaped the framework of dermatological education. A strong Eurocentric bias has shaped our understanding of the genetic architecture of pigmentary traits, which influences the ways in we understand the evolutionary processes leading to modern pigmentation diversity. Finally, I discuss how these biases in pigmentation genetics work in combination with phenotypic systems that privilege predicting lighter pigmentation variation to impede accurate prediction of intermediate phenotypes, particularly in individuals with ancestry from multiple populations. This can lead to a disproportionate targeting of already over-policed populations with darker skin. CONCLUSIONS Potential changes to how we conceptualize clinical and basic pigmentation research may help to reduce existing health disparities and improve understanding of pigmentation genetic architecture and how this knowledge is applied in forensic contexts.
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Affiliation(s)
- Heather L Norton
- Department of Anthropology, University of Cincinnati, Cincinnati, Ohio, USA
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6
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Le L, Escobar IE, Ho T, Lefkovith AJ, Latteri E, Haltaufderhyde KD, Dennis MK, Plowright L, Sviderskaya EV, Bennett DC, Oancea E, Marks MS. SLC45A2 protein stability and regulation of melanosome pH determine melanocyte pigmentation. Mol Biol Cell 2020; 31:2687-2702. [PMID: 32966160 PMCID: PMC7927184 DOI: 10.1091/mbc.e20-03-0200] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
SLC45A2 encodes a putative transporter expressed primarily in pigment cells. SLC45A2 mutations cause oculocutaneous albinism type 4 (OCA4) and polymorphisms are associated with pigmentation variation, but the localization, function, and regulation of SLC45A2 and its variants remain unknown. We show that SLC45A2 localizes to a cohort of mature melanosomes that only partially overlaps with the cohort expressing the chloride channel OCA2. SLC45A2 expressed ectopically in HeLa cells localizes to lysosomes and raises lysosomal pH, suggesting that in melanocytes SLC45A2 expression, like OCA2 expression, results in the deacidification of maturing melanosomes to support melanin synthesis. Interestingly, OCA2 overexpression compensates for loss of SLC45A2 expression in pigmentation. Analyses of SLC45A2- and OCA2-deficient mouse melanocytes show that SLC45A2 likely functions later during melanosome maturation than OCA2. Moreover, the light skin-associated SLC45A2 allelic F374 variant restores only moderate pigmentation to SLC45A2-deficient melanocytes due to rapid proteasome-dependent degradation resulting in lower protein expression levels in melanosomes than the dark skin-associated allelic L374 variant. Our data suggest that SLC45A2 maintains melanosome neutralization that is initially orchestrated by transient OCA2 activity to support melanization at late stages of melanosome maturation, and that a common allelic variant imparts reduced activity due to protein instability.
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Affiliation(s)
- Linh Le
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Iliana E Escobar
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912
| | - Tina Ho
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Ariel J Lefkovith
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and.,Cell and Molecular Biology Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
| | - Emily Latteri
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and
| | - Kirk D Haltaufderhyde
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912
| | - Megan K Dennis
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and.,Biology Department, Marist College, Poughkeepsie, NY 12601
| | - Lynn Plowright
- Molecular & Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Elena V Sviderskaya
- Molecular & Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Dorothy C Bennett
- Molecular & Clinical Sciences Research Institute, St George's, University of London, London SW17 0RE, UK
| | - Elena Oancea
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI 02912
| | - Michael S Marks
- Department of Pathology & Laboratory Medicine, Children's Hospital of Philadelphia, Philadelphia, PA 19104.,Department of Pathology and Laboratory Medicine and Department of Physiology and
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7
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Jonnalagadda M, Faizan MA, Ozarkar S, Ashma R, Kulkarni S, Norton HL, Parra E. A Genome-Wide Association Study of Skin and Iris Pigmentation among Individuals of South Asian Ancestry. Genome Biol Evol 2019; 11:1066-1076. [PMID: 30895295 PMCID: PMC6456006 DOI: 10.1093/gbe/evz057] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/19/2019] [Indexed: 12/14/2022] Open
Abstract
South Asia has a complex history of migrations and is characterized by substantial pigmentary and genetic diversity. For this reason, it is an ideal region to study the genetic architecture of normal pigmentation variation. Here, we present a meta-analysis of two genome-wide association studies (GWASs) of skin pigmentation using skin reflectance (M-index) as a quantitative phenotype. The meta-analysis includes a sample of individuals of South Asian descent living in Canada (N = 348), and a sample of individuals from two caste and four tribal groups from West Maharashtra, India (N = 480). We also present the first GWAS of iris color in South Asian populations. This GWAS was based on quantitative measures of iris color obtained from high-resolution iris pictures. We identified genome-wide significant associations of variants within the well-known gene SLC24A5, including the nonsynonymous rs1426654 polymorphism, with both skin pigmentation and iris color, highlighting the pleiotropic effects of this gene on pigmentation. Variants in the HERC2 gene (e.g., rs12913832) were also associated with iris color and iris heterochromia. Our study emphasizes the usefulness of quantitative methods to study iris color variation. We also identified novel genome-wide significant associations with skin pigmentation and iris color, but we could not replicate these associations due to the lack of independent samples. It will be critical to expand the number of studies in South Asian populations in order to better understand the genetic variation driving the diversity of skin pigmentation and iris color observed in this region.
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Affiliation(s)
- Manjari Jonnalagadda
- Symbiosis School for Liberal Arts, Symbiosis International (Deemed University), Pune, India
| | | | - Shantanu Ozarkar
- Department of Anthropology, Savitribai Phule Pune University, India
| | - Richa Ashma
- Department of Zoology, Savitribai Phule Pune University, India
| | - Shaunak Kulkarni
- Department of Anthropology, Savitribai Phule Pune University, India
| | | | - Esteban Parra
- Department of Anthropology, University of Toronto, Ontario, Canada
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8
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Quillen EE, Norton HL, Parra EJ, Lona-Durazo F, Ang KC, Illiescu FM, Pearson LN, Shriver MD, Lasisi T, Gokcumen O, Starr I, Lin YL, Martin AR, Jablonski NG. Shades of complexity: New perspectives on the evolution and genetic architecture of human skin. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2018; 168 Suppl 67:4-26. [PMID: 30408154 DOI: 10.1002/ajpa.23737] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 09/17/2018] [Accepted: 09/20/2018] [Indexed: 02/06/2023]
Abstract
Like many highly variable human traits, more than a dozen genes are known to contribute to the full range of skin color. However, the historical bias in favor of genetic studies in European and European-derived populations has blinded us to the magnitude of pigmentation's complexity. As deliberate efforts are being made to better characterize diverse global populations and new sequencing technologies, better measurement tools, functional assessments, predictive modeling, and ancient DNA analyses become more widely accessible, we are beginning to appreciate how limited our understanding of the genetic bases of human skin color have been. Novel variants in genes not previously linked to pigmentation have been identified and evidence is mounting that there are hundreds more variants yet to be found. Even for genes that have been exhaustively characterized in European populations like MC1R, OCA2, and SLC24A5, research in previously understudied groups is leading to a new appreciation of the degree to which genetic diversity, epistatic interactions, pleiotropy, admixture, global and local adaptation, and cultural practices operate in population-specific ways to shape the genetic architecture of skin color. Furthermore, we are coming to terms with how factors like tanning response and barrier function may also have influenced selection on skin throughout human history. By examining how our knowledge of pigmentation genetics has shifted in the last decade, we can better appreciate how far we have come in understanding human diversity and the still long road ahead for understanding many complex human traits.
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Affiliation(s)
- Ellen E Quillen
- Department of Internal Medicine, Section of Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina.,Center for Precision Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina
| | - Heather L Norton
- Department of Anthropology, University of Cincinnati, Cincinnati, Ohio
| | - Esteban J Parra
- Department of Anthropology, University of Toronto - Mississauga, Mississauga, Ontario, Canada
| | - Frida Lona-Durazo
- Department of Anthropology, University of Toronto - Mississauga, Mississauga, Ontario, Canada
| | - Khai C Ang
- Department of Pathology and Jake Gittlen Laboratories for Cancer Research, Penn State College of Medicine, Hershey, Pennsylvania
| | - Florin Mircea Illiescu
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Centro de Estudios Interculturales e Indígenas - CIIR, P. Universidad Católica de Chile, Santiago, Chile
| | - Laurel N Pearson
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Mark D Shriver
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Tina Lasisi
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
| | - Omer Gokcumen
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York
| | - Izzy Starr
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York
| | - Yen-Lung Lin
- Department of Biological Sciences, State University of New York at Buffalo, Buffalo, New York
| | - Alicia R Martin
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts.,Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, Massachusetts.,Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, Massachusetts
| | - Nina G Jablonski
- Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania
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9
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Iliescu FM, Chaplin G, Rai N, Jacobs GS, Basu Mallick C, Mishra A, Thangaraj K, Jablonski NG. The influences of genes, the environment, and social factors on the evolution of skin color diversity in India. Am J Hum Biol 2018; 30:e23170. [PMID: 30099804 DOI: 10.1002/ajhb.23170] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 06/18/2018] [Accepted: 07/09/2018] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVES Skin color is a highly visible and variable trait across human populations. It is not yet clear how evolutionary forces interact to generate phenotypic diversity. Here, we sought to unravel through an integrative framework the role played by three factors-demography and migration, sexual selection, and natural selection-in driving skin color diversity in India. METHODS Skin reflectance data were collected from 10 diverse socio-cultural populations along the latitudinal expanse of India, including both sexes. We first looked at how skin color varies within and between these populations. Second, we compared patterns of sexual dimorphism in skin color. Third, we studied the influence of ultraviolet radiation on skin color throughout India. Finally, we attempted to disentangle the interactions between these factors in the context of available genetic data. RESULTS We found that the relative importance of these forces varied between populations. Social factors and population structure have played a stronger role than natural selection in shaping skin color diversity across India. Phenotypic overprinting resulted from additional genetic mutations overriding the skin lightening effect of variants such as the SLC24A5 rs1426654-A allele in some populations, in the context of the variable influence of sexual selection. Furthermore, specific genotypes are not associated reliably with specific skin color phenotypes. This result has relevance for DNA forensics and ancient DNA research. CONCLUSIONS India is a crucible of macro- and micro-evolutionary forces, and the complex interactions of physical and social forces are visible in the patterns of skin color seen today in the country.
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Affiliation(s)
- Florin Mircea Iliescu
- Department of Zoology, University of Cambridge, Cambridge, United Kingdom.,Centro de Estudios Interculturales e Indígenas - CIIR, P. Universidad Católica de Chile, Santiago, Chile
| | - George Chaplin
- Department of Anthropology, The Pennsylvania State University, University Park, State Park, Pennsylvania
| | - Niraj Rai
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India.,Birbal Sahni Institute of Palaeosciences, Lucknow, India
| | - Guy S Jacobs
- Complexity Institute, Nanyang Technological University, Singapore
| | - Chandana Basu Mallick
- Estonian Biocentre, Tartu, Estonia.,The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, United Kingdom
| | - Anshuman Mishra
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | - Nina G Jablonski
- Department of Anthropology, The Pennsylvania State University, University Park, State Park, Pennsylvania
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10
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Sarkar A, Nandineni MR. Association of common genetic variants with human skin color variation in Indian populations. Am J Hum Biol 2017; 30. [PMID: 28984396 DOI: 10.1002/ajhb.23068] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 08/21/2017] [Accepted: 09/21/2017] [Indexed: 12/13/2022] Open
Abstract
OBJECTIVES Human skin color is one of the most conspicuously variable physical traits that has attracted the attention of physical anthropologists, social scientists and human geneticists. Although several studies have established the underlying genes and their variants affecting human skin color, they were mostly confined to Europeans and Africans and similar studies in Indian populations have been scanty. Studying the association between candidate genetic variants and skin color will help to validate previous findings and to better understand the molecular mechanism of skin color variation. METHODS In this study, 22 candidate SNPs from 12 genes were tested for association with skin color in 299 unrelated samples sourced from nine geographical locations in India. RESULTS Our study establishes the association of 9 SNPs with the phenotype in Indian populations and could explain ∼31% of the variance in skin color. Haplotype analysis of chromosome 15 revealed a significant association of alleles G, A and C of SNPs rs1426654, rs11070627, and rs12913316, respectively, to the phenotype, and accounted for 17% of the variance. Latitude of the sampling location was also a significant factor, contributing to ∼19% of the variation observed in the samples. CONCLUSIONS These observations support the findings that rs1426654 and rs4775730 located in SLC24A5, and rs11070627 and rs12913316 located in MYEF2 and CTXN2 genes respectively, are major contributors toward skin pigmentation and would aid in further unraveling the genotype-phenotype association in Indian populations. These findings can be utilized in forensic DNA applications for criminal investigations.
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Affiliation(s)
- Anujit Sarkar
- Laboratory of Genomics and Profiling Applications, Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, Telangana, 500001, India.,Graduate studies, Manipal University, Manipal, 576104, India
| | - Madhusudan R Nandineni
- Laboratory of Genomics and Profiling Applications, Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, Telangana, 500001, India.,Laboratory of DNA Fingerprinting Services, Centre for DNA Fingerprinting and Diagnostics (CDFD), Hyderabad, Telangana, 500001, India
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11
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Walsh S, Chaitanya L, Breslin K, Muralidharan C, Bronikowska A, Pospiech E, Koller J, Kovatsi L, Wollstein A, Branicki W, Liu F, Kayser M. Global skin colour prediction from DNA. Hum Genet 2017; 136:847-863. [PMID: 28500464 PMCID: PMC5487854 DOI: 10.1007/s00439-017-1808-5] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 05/03/2017] [Indexed: 12/14/2022]
Abstract
Human skin colour is highly heritable and externally visible with relevance in medical, forensic, and anthropological genetics. Although eye and hair colour can already be predicted with high accuracies from small sets of carefully selected DNA markers, knowledge about the genetic predictability of skin colour is limited. Here, we investigate the skin colour predictive value of 77 single-nucleotide polymorphisms (SNPs) from 37 genetic loci previously associated with human pigmentation using 2025 individuals from 31 global populations. We identified a minimal set of 36 highly informative skin colour predictive SNPs and developed a statistical prediction model capable of skin colour prediction on a global scale. Average cross-validated prediction accuracies expressed as area under the receiver-operating characteristic curve (AUC) ± standard deviation were 0.97 ± 0.02 for Light, 0.83 ± 0.11 for Dark, and 0.96 ± 0.03 for Dark-Black. When using a 5-category, this resulted in 0.74 ± 0.05 for Very Pale, 0.72 ± 0.03 for Pale, 0.73 ± 0.03 for Intermediate, 0.87±0.1 for Dark, and 0.97 ± 0.03 for Dark-Black. A comparative analysis in 194 independent samples from 17 populations demonstrated that our model outperformed a previously proposed 10-SNP-classifier approach with AUCs rising from 0.79 to 0.82 for White, comparable at the intermediate level of 0.63 and 0.62, respectively, and a large increase from 0.64 to 0.92 for Black. Overall, this study demonstrates that the chosen DNA markers and prediction model, particularly the 5-category level; allow skin colour predictions within and between continental regions for the first time, which will serve as a valuable resource for future applications in forensic and anthropologic genetics.
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Affiliation(s)
- Susan Walsh
- Department of Biology, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, IN, USA.
| | - Lakshmi Chaitanya
- Department of Genetic Identification, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Krystal Breslin
- Department of Biology, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, IN, USA
| | - Charanya Muralidharan
- Department of Biology, Indiana University Purdue University Indianapolis (IUPUI), Indianapolis, IN, USA
| | - Agnieszka Bronikowska
- Department of Dermatology, Collegium Medicum of the Jagiellonian University, Kraków, Poland
| | - Ewelina Pospiech
- Faculty of Biology and Earth Sciences, Institute of Zoology, Jagiellonian University, Kraków, Poland
- Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
| | - Julia Koller
- Department of Genetic Identification, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Leda Kovatsi
- Laboratory of Forensic Medicine and Toxicology, School of Medicine, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Andreas Wollstein
- Section of Evolutionary Biology, Department of Biology II, University of Munich LMU, Planegg-Martinsried, Germany
| | - Wojciech Branicki
- Malopolska Centre of Biotechnology, Jagiellonian University, Kraków, Poland
- Central Forensic Laboratory of the Police, Warsaw, Poland
| | - Fan Liu
- Department of Genetic Identification, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands
- Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Manfred Kayser
- Department of Genetic Identification, Erasmus MC University Medical Centre Rotterdam, Rotterdam, The Netherlands.
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Jonnalagadda M, Bharti N, Patil Y, Ozarkar S, K SM, Joshi R, Norton H. Identifying signatures of positive selection in pigmentation genes in two South Asian populations. Am J Hum Biol 2017; 29. [PMID: 28439965 DOI: 10.1002/ajhb.23012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 02/14/2017] [Accepted: 04/01/2017] [Indexed: 11/08/2022] Open
Abstract
OBJECTIVES Skin pigmentation is a polygenic trait showing wide phenotypic variations among global populations. While numerous pigmentation genes have been identified to be under positive selection among European and East populations, genes contributing to phenotypic variation in skin pigmentation within and among South Asian populations are still poorly understood. The present study uses data from the Phase 3 of the 1000 genomes project focusing on two South Asian populations-GIH (Gujarati Indian from Houston, Texas) and ITU (Indian Telugu from UK), so as to decode the genetic architecture involved in adaptation to ultraviolet radiation in South Asian populations. METHODS Statistical tests included were (1) tests to identify deviations of the Site Frequency Spectrum (SFS) from neutral expectations (Tajima's D, Fay and Wu's H and Fu and Li's D* and F*), (2) tests focused on the identification of high-frequency haplotypes with extended linkage disequilibrium (iHS and Rsb), and (3) tests based on genetic differentiation between populations (LSBL). RESULTS Twenty-two pigmentation genes fall in the top 1% for at least one statistic in the GIH population, 5 of which (LYST, OCA2, SLC24A5, SLC45A2, and TYR) have been previously associated with normal variation in skin, hair, or eye color. In comparison, 17 genes fall in the top 1% for at least one statistic in the ITU population. Twelve loci which are identified as outliers in the ITU scan were also identified in the GIH population. CONCLUSIONS These results suggest that selection may have affected these loci broadly across the region.
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Affiliation(s)
- Manjari Jonnalagadda
- Symbiosis School for Liberal Arts (SSLA), Symbiosis International University (SIU), Pune, 411014, India
| | - Neeraj Bharti
- HPC-MBA Group, Centre for Development of Advanced Computing, Pune, 411007, India
| | - Yatish Patil
- HPC-MBA Group, Centre for Development of Advanced Computing, Pune, 411007, India
| | - Shantanu Ozarkar
- Department of Anthropology, Savitribai Phule Pune University, Pune, 411007, India
| | - Sunitha Manjari K
- HPC-MBA Group, Centre for Development of Advanced Computing, Pune, 411007, India
| | - Rajendra Joshi
- HPC-MBA Group, Centre for Development of Advanced Computing, Pune, 411007, India
| | - Heather Norton
- Department of Anthropology, University of Cincinnati, Cincinnati, Ohio
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Identification of a novel locus associated with skin colour in African-admixed populations. Sci Rep 2017; 7:44548. [PMID: 28300201 PMCID: PMC5353593 DOI: 10.1038/srep44548] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 01/23/2017] [Indexed: 11/30/2022] Open
Abstract
Skin pigmentation is a complex trait that varies largely among populations. Most genome-wide association studies of this trait have been performed in Europeans and Asians. We aimed to uncover genes influencing skin colour in African-admixed individuals. We performed a genome-wide association study of melanin levels in 285 Hispanic/Latino individuals from Puerto Rico, analyzing 14 million genetic variants. A total of 82 variants with p-value ≤1 × 10−5 were followed up in 373 African Americans. Fourteen single nucleotide polymorphisms were replicated, of which nine were associated with skin colour at genome-wide significance in a meta-analysis across the two studies. These results validated the association of two previously known skin pigmentation genes, SLC24A5 (minimum p = 2.62 × 10−14, rs1426654) and SLC45A2 (minimum p = 9.71 × 10−10, rs16891982), and revealed the intergenic region of BEND7 and PRPF18 as a novel locus associated with this trait (minimum p = 4.58 × 10−9, rs6602666). The most significant variant within this region is common among African-descent populations but not among Europeans or Native Americans. Our findings support the advantages of analyzing African-admixed populations to discover new genes influencing skin pigmentation.
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Mishra A, Nizammuddin S, Mallick CB, Singh S, Prakash S, Siddiqui NA, Rai N, Carlus SJ, Sudhakar DVS, Tripathi VP, Möls M, Kim-Howard X, Dewangan H, Mishra A, Reddy AG, Roy B, Pandey K, Chaubey G, Das P, Nath SK, Singh L, Thangaraj K. Genotype-Phenotype Study of the Middle Gangetic Plain in India Shows Association of rs2470102 with Skin Pigmentation. J Invest Dermatol 2016; 137:670-677. [PMID: 27866970 DOI: 10.1016/j.jid.2016.10.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Revised: 10/15/2016] [Accepted: 10/17/2016] [Indexed: 02/06/2023]
Abstract
Our understanding of the genetics of skin pigmentation has been largely skewed towards populations of European ancestry, imparting less attention to South Asian populations, who behold huge pigmentation diversity. Here, we investigate skin pigmentation variation in a cohort of 1,167 individuals in the Middle Gangetic Plain of the Indian subcontinent. Our data confirm the association of rs1426654 with skin pigmentation among South Asians, consistent with previous studies, and also show association for rs2470102 single nucleotide polymorphism. Our haplotype analyses further help us delineate the haplotype distribution across social categories and skin color. Taken together, our findings suggest that the social structure defined by the caste system in India has a profound influence on the skin pigmentation patterns of the subcontinent. In particular, social category and associated single nucleotide polymorphisms explain about 32% and 6.4%, respectively, of the total phenotypic variance. Phylogeography of the associated single nucleotide polymorphisms studied across 52 diverse populations of the Indian subcontinent shows wide presence of the derived alleles, although their frequencies vary across populations. Our results show that both polymorphisms (rs1426654 and rs2470102) play an important role in the skin pigmentation diversity of South Asians.
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Affiliation(s)
- Anshuman Mishra
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | - Chandana Basu Mallick
- Department of Evolutionary Biology, Institute of Molecular and Cell Biology, University of Tartu, Tartu, Estonia; Estonian Biocentre, Tartu, Estonia
| | - Sakshi Singh
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Satya Prakash
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | - Niraj Rai
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - S Justin Carlus
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | | | - Vishnu P Tripathi
- Department of Biotechnology, V.B.S. Purvanchal University, Jaunpur, India
| | - Märt Möls
- Estonian Biocentre, Tartu, Estonia; Insitute of Mathematical Statistics, University of Tartu, Tartu, Estonia
| | - Xana Kim-Howard
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma, USA
| | | | | | - Alla G Reddy
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Biswajit Roy
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Krishna Pandey
- Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | | | - Pradeep Das
- Rajendra Memorial Research Institute of Medical Sciences (ICMR), Patna, India
| | - Swapan K Nath
- Arthritis and Clinical Immunology Research Program, Oklahoma Medical Research Foundation, Oklahoma, USA
| | - Lalji Singh
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
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