A distinctive pigment of the skin in New Guinea indigenes

Walsh, R. J.

doi:10.1111/j.1469-1809.1971.tb00250.x

Cited by 21 publications

(5 citation statements)

References 7 publications

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“…Brown OCA was initially identified in a Nigerian population (93) and was found to be prevalent in the Black or Negroid population of Africa and America (94). Rufous OCA was initially reported in the Black population of Africa and Papua New Guinea (95,96). Brown and Rufous OCA have been identified in individuals with type III -V skin color only and are physically distinguished based on skin and hair color (96).…”

Section: Oculocutaneous Albinism In Humans (Oca3)mentioning

confidence: 99%

Tyrp1 and Oculocutaneous Albinism Type 3

Sarangarajan

Boissy

2001

Pigment Cell Research

113

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addition to its role in eumelanin synthesis, Tyrp1 is involved in Tyrosinase-related protein 1 (Tyrp1) is a melanocyte-specific maintaining stability of tyrosinase protein and modulating its gene product involved in eumelanin synthesis. Mutations in the catalytic activity. Tyrp1 is also involved in maintenance of mouse Tyrp1 gene are associated with brown pelage, and in the human TYRP1 gene with oculocutaneous albinism type 3 melanosome ultrastructure and affects melanocyte prolifera-(OCA3). In the murine system, Tyrp1 expresses significant tion and melanocyte cell death. The current review is an dihydroxyindole carboxylic acid oxidase (i.e. DHICA oxattempt to consolidate our understanding of the role of Tyrp1 idase) activity. However, in humans, TYRP1 is enigmatic in in the melanocyte. that despite extensive efforts focused on the study of its Key words: Pigmentation, Tyrosine hydroxylase, Brown/Rufunction, its actual role in the human melanocyte is still fous Albinism, Brown locus, Protein trafficking unclear. There is mounting evidence demonstrating that in Mutations in the genes encoding some of the enzymes and regulatory proteins involved in melanin synthesis result in various forms of oculocutaneous albinism (OCA). OCA1 correlates with mutations in the tyrosinase (TYR) gene (7). Most individuals with OCA1 have completely amelanotic skin, hair and eyes with the inability to tan (i.e. OCA1A). However, some nucleotide lesions of the TYR gene result in a partially functional enzyme so that individuals with this subtype of OCA1 can exhibit moderate levels of skin and hair pigmentation and the ability to tan (i.e. OCA1B). OCA2 correlates with mutations in the P gene (8). Individuals with OCA2 present with minimal to moderate amounts of pigment remaining in the skin, hair and eyes, many of whom can develop pigmented freckles, lentigines and/or nevi with age. OCA3 correlates with mutations in the TYRP1 gene (9). Individuals with OCA3 present with minimal pigment reduction in the skin, hair and eyes. This form of albinism was previously referred to as Rufous and possibly some forms of Brown albinism.

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Section: Oculocutaneous Albinism In Humans (Oca3)mentioning

confidence: 99%

Tyrp1 and Oculocutaneous Albinism Type 3

Sarangarajan

Boissy

2001

Pigment Cell Research

113

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“…The last published investigation of albinism in the Pacific region were phenotype descriptive studies of OCA(s) in Papua New Guinea. [36][37][38][39] The clinical phenotype of one form of albinism termed 'Red-skinned' in the Micronesians of Papua New Guinea has been defined in two published studies. 36,38 The most extensive albinism research in the Pacific in the past few years has involved a photographic project undertaken in collaboration with the National Organization for Albinism and Hypopigmentation of the albinism world alliance (www.positiveexposure.org).…”

Section: Introductionmentioning

confidence: 99%

“…[36][37][38][39] The clinical phenotype of one form of albinism termed 'Red-skinned' in the Micronesians of Papua New Guinea has been defined in two published studies. 36,38 The most extensive albinism research in the Pacific in the past few years has involved a photographic project undertaken in collaboration with the National Organization for Albinism and Hypopigmentation of the albinism world alliance (www.positiveexposure.org). There has been little published about albinism in the Polynesians of the South Pacific; moreover, there are no published data of genetic analysis combined with phenotype classification, for OCA in the South Pacific Region.…”

Section: Introductionmentioning

confidence: 99%

Inheritance of a novel mutated allele of the OCA2 gene associated with high incidence of oculocutaneous albinism in a Polynesian community

et al. 2009

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Oculocutaneous albinism type 2 (OCA2) is a human autosomal-recessive hypopigmentation disorder associated with pathological mutations of the OCA2 gene. In this study, we investigated a form of OCA in a Polynesian population with an observed phenotype characterized by fair skin, some brown nevi present in the sun-exposed areas and green or blue eyes. Hair presented with a unique red coloration since birth, with tones ranging across individuals from Yellow-Red to Brown-Red, or Auburn. We genetically screened for mutations in the OCA2 and MC1R genes as their products have previously been shown to be associated with red hair/fair skin and OCA2. The SLC45A2 gene was also screened to identify any possible relation to skin color variation. We have identified a novel missense substitution in the OCA2 gene (Gly775Asp) responsible for OCA2 in individuals of Polynesian heritage from Tuvalu. The estimated incidence of this form of OCA2 in the primary study community is believed to occur at one of the highest recorded rates of albinism at approximately 1 per 669 individuals. In addition, we have analyzed four unrelated individuals with albinism who have Polynesian heritage from three other separate communities and found they carry the same OCA2 mutation. We also analyzed an out-group comprising three unrelated individuals with albinism of Melanesian ancestries from two separate communities, one Australian Aboriginal and three Australian Caucasians, and did not detect this mutation. We hypothesize that this mutation may be Polynesian specific and that it originated from a common founder.

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“…BOCA initially was defined in the Nigerian population (King et al 1980) and only has been found to occur in the Black, or Negroid, populations of Africa and America (King et al 1985). ROCA principally has been reported in the Black populations of Africa and Papua New Guinea (Stannus 1913;Walsh 1971; Kromberg et al 1990). In southern Africa, ROCA occurs at a prevalence of -1/8,500 individuals (Kromberg et al.…”

Section: Introductionmentioning

confidence: 99%

Rufous Oculocutaneous Albinism in Southern African Blacks Is Caused by Mutations in the TYRP1 Gene

Manga

Kromberg

Box

et al. 1997

The American Journal of Human Genetics

136

104

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Oculocutaneous albinism (OCA) is the most common autosomal recessive disorder among southern African Blacks. There are three forms that account for almost all OCA types in this region. Tyrosinase-positive OCA (OCA2), which is the most common, affects approximately 1/3,900 newborns and has a carrier frequency of approximately 1/33. It is caused by mutations in the P gene on chromosome 15. Brown OCA (BOCA) and rufous OCA (ROCA) account for the majority of the remaining phenotypes. The prevalence of BOCA is unknown, but for ROCA it is approximately 1/8,500. Linkage analysis performed on nine ROCA families showed that ROCA was linked to an intragenic marker at the TYRP1 locus (maximum LOD score = 3.80 at straight theta=.00). Mutation analysis of 19 unrelated ROCA individuals revealed a nonsense mutation at codon 166 (S166X) in 17 (45%) of 38 ROCA chromosomes, and a second mutation (368delA) was found in an additional 19 (50%) of 38 chromosomes; mutations were not identified in the remaining 2 ROCA chromosomes. In one family, two siblings with a phenotypically unclassified form of albinism were found to be compound heterozygotes for mutations (S166X/368delA) at the TYRP1 locus and were heterozygous for a common 2.7-kb deletion in the P gene. These findings have highlighted the influence of genetic background on phenotype, in which the genotype at one locus can be influenced by the genotype at a second locus, leading to a modified phenotype. ROCA, which in southern African Blacks is caused by mutations in the TYRP1 gene, therefore should be referred to as "OCA3," since this is the third locus that has been shown to cause an OCA phenotype in humans.

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A distinctive pigment of the skin in New Guinea indigenes

Cited by 21 publications

References 7 publications

Tyrp1 and Oculocutaneous Albinism Type 3

Tyrp1 and Oculocutaneous Albinism Type 3

Inheritance of a novel mutated allele of the OCA2 gene associated with high incidence of oculocutaneous albinism in a Polynesian community

Rufous Oculocutaneous Albinism in Southern African Blacks Is Caused by Mutations in the TYRP1 Gene

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