title: In Southern Africa, brown oculocutaneous albinism (BOCA) maps to the OCA2 locus on chromosome 15q: P-gene mutations identified.
abstract: In southern Africa, brown oculocutaneous albinism (BOCA) is a distinct pigmentation phenotype. In at least two cases, it has occurred in the same families as tyrosinase-positive oculocutaneous albinism (OCA2), suggesting that it may be allelic, despite the fact that this phenotype was attributed to mutations in the TYRP1 gene in an American individual of mixed ancestry. Linkage analysis in five families mapped the BOCA locus to the same region as the OCA2 locus (maximum LOD 3.07; theta=0 using a six-marker haplotype). Mutation analysis of the human homologue of the mouse pink-eyed dilution gene (P), in 10 unrelated individuals with BOCA revealed that 9 had one copy of the 2.7-kb deletion. No other mutations were identified. Additional haplotype studies, based on closely linked markers (telomere to centromere: D15S1048, D15S1019, D15S1533, P-gene 2.7-kb deletion, D15S219, and D15S156) revealed several BOCA-associated P haplotypes. These could be divided into two core haplotypes, suggesting that a limited number of P-gene mutations give rise to this phenotype.
authors.affiliation: Department of Human Genetics, School of Pathology, The South African Institute for Medical Research and University of the Witwatersrand, Johannesburg, 2000, South Africa.
authors.forename: P
authors.initials: P
authors.lastname: Manga
authors.forename: J
authors.initials: J
authors.lastname: Kromberg
authors.forename: A
authors.initials: A
authors.lastname: Turner
authors.forename: T
authors.initials: T
authors.lastname: Jenkins
authors.forename: M
authors.initials: M
authors.lastname: Ramsay
mesh_terms: D016115:Albinism, Oculocutaneous / Q000201:enzymology / Q000235:genetics*; D044383:Black People / Q000235:genetics; D002352:Carrier Proteins; D002503:Centromere; D002874:Chromosome Mapping; D002884:Chromosomes, Human, Pair 15; D005260:Female; D005819:Genetic Markers; D006239:Haplotypes; D006801:Humans; D008126:Lod Score; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D014442:Monophenol Monooxygenase / Q000235:genetics*; D010088:Oxidoreductases; D010375:Pedigree; D017384:Sequence Deletion; D013019:South Africa; D016615:Telomere
chemical_list: D002352:Carrier Proteins; D005819:Genetic Markers; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C076239:P protein, mouse; D010088:Oxidoreductases; C489799:TYRP1 protein, human; D014442:Monophenol Monooxygenase