Albinism in Nigeria. A clinical and social study.
ABSTRACT A study of 1000 Nigerian albinos, all of Negro stock, showed various types of albinism with their different modes of transmission--oculocutaneous, ocular and cutaneous. The much higher incidence among the more settled communities in the south, compared with the more nomadic communities in the north, may be related to greater inbreeding tendencies in the south. The sun and society are hostile to the albinos. Under the tropical sunshine, their melanin-deficient skin develops wrinkles, lentigines, actinic keratoses and epitheliomata from which they may die in early adult life or in middle age. Myopia and other ocular defects retard the progress of many albinos in school and they eventually drop out to seek disastrous menial outdoor occupations. Registering albinos early in life, assuring their families that albino defects are confined to the skin and eyes, advising on protective clothing and sun-screening agents, correcting myopia, assisting with indooor occupations, and early treatment of actinic keratoses and skin cancer should help many albinos to attain social acceptance and a ripe old age.
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ABSTRACT: Skin cancer is rare among Africans and albinism is an established risk for skin cancer in this population. Ultraviolet radiation is highest at the equator and African albinos living close to the equator have the highest risk of developing skin cancers. This was a retrospective study that involved histological review of all specimens with skin cancers from African albinos submitted to The Regional Dermatology Training Center in Moshi, Tanzania from 2002 to 2011. A total of 134 biopsies from 86 patients with a male to female ratio of 1:1 were reviewed. Head and neck was the commonest (n = 75, 56.0%) site affected by skin cancers. Squamous cell carcinoma (SCC) was more common than basal cell carcinoma (BCC) with a ratio of 1.2:1. Only one Acral lentiginous melanoma was reported. Majority (55.6%) of SCC were well differentiated while nodular BCC (75%) was the most common type of BCC. Squamous cell carcinoma is more common than basal cell carcinoma in African albinos.BMC Cancer 03/2014; 14(1):157. · 3.33 Impact Factor
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ABSTRACT: Melanin provides a crucial filter for solar UV radiation and its genetically determined variation influences both skin pigmentation and risk of cancer. Genetic evidence suggests that the acquisition of a highly stable melanocortin 1 receptor allele promoting black pigmentation arose around the time of savannah colonization by hominins at some 1-2 Ma. The adaptive significance of dark skin is generally believed to be protection from UV damage but the pathologies that might have had a deleterious impact on survival and/or reproductive fitness, though much debated, are uncertain. Here, I suggest that data on age-associated cancer incidence and lethality in albinos living at low latitudes in both Africa and Central America support the contention that skin cancer could have provided a potent selective force for the emergence of black skin in early hominins.Proceedings of the Royal Society B: Biological Sciences 01/2014; 281(1781):20132955. · 5.68 Impact Factor
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ABSTRACT: Oculocutaneous albinism (OCA) is a heterogeneous group of autosomal recessive disorders resulting from mutations of the tyrosinase (TYR) gene and presents with either complete or partial absence of pigment in the skin, hair and eyes due to a defect in an enzyme involved in the production of melanin. In this study, mutations in the TYR gene of 30 unrelated Iranian OCA1 patients and 100 healthy individuals were examined using PCR-sequencing. Additionally, in order to predict the possible effects of new mutations on the structure and function of tyrosinase, these mutations were analyzed by SIFT, PolyPhen and I-Mutant 2 software. Here, two new pathogenic p.C89S and p.H180R mutations were detected in two OCA1 patients. Moreover, the R402Q and S192Y variants, which are common non-pathogenic polymorphisms, were detected in 17.5% and 35% of the patients, respectively. The outcome of this study has extended the genotypic spectrum of OCA1 patients, which paves the way for more efficient carrier detection and genetic counseling.09/2014;