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.
- SourceAvailable from: scielo.br[Show abstract] [Hide abstract]
ABSTRACT: OBJECTIVES: To evaluate the laboratories methods of the oculocutaneous albinism (OCA 1and OCA 2) of descriptive form and to analyze its results. METHODS: The hair bulb test is a chemical method used to distinguish the two forms, however, recently had its effectiveness as an standard test contested. The advance of molecular biology allows the analysis of the mutations that cause the disturb and its genic location. CONCLUSIONS: The bulb test is secure only for the diagnosis of OCA 1A, being able to be used as complement of a more refined method. The molecular analysis supplies a diagnostic definitive allowing to distinguish OCA 1 from OCA 2, because the mutations affect genes in different chromosomes.Jornal Brasileiro de Patologia e Medicina Laboratorial 02/2007; 43(1):25-30.
- [Show abstract] [Hide abstract]
ABSTRACT: Oculocutaneous albinism (OCA) is an autosomal recessive disorder caused by either complete lack of or a reduction of melanin biosynthesis in the melanocytes. The OCA1A is the most severe type with a complete lack of melanin production throughout life, while the milder forms OCA1B, OCA2, OCA3, and OCA4 show some pigment accumulation over time. Mutations in TYR, OCA2, TYRP1, and SLC45A2 are mainly responsible for causing oculocutaneous albinism. Recently, two new genes SLC24A5 and C10orf11 are identified that are responsible to cause OCA6 and OCA7, respectively. Also a locus has been mapped to the human chromosome 4q24 region which is responsible for genetic cause of OCA5. In this paper, we summarized the clinical and molecular features of OCA genes. Further, we reviewed the screening of pathological mutations of OCA genes and its molecular mechanism of the protein upon mutation by in silico approach. We also reviewed TYR (T373K, N371Y, M370T, and P313R), OCA2 (R305W), TYRP1 (R326H and R356Q) mutations and their structural consequences at molecular level. It is observed that the pathological genetic mutations and their structural and functional significance of OCA genes will aid in development of personalized medicine for albinism patients.BioMed Research International 01/2014; 2014:905472. · 2.71 Impact Factor
- [Show abstract] [Hide abstract]
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.PLoS ONE 09/2014; · 3.53 Impact Factor