Articles: black-people-genetics.
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Since the cloning of the cystic fibrosis (CF) gene and the identification of delta F508, the most common CF mutation, screening the general population for CF has been vigorously debated. Adding to the controversy is the question of whether screening should be offered to African Americans, whose incidence of CF (1/17,000) is much lower than that of whites (1/2500). We tested for five common mutations (delta F508, G551D, G542X, R553X, and N1303K) in order to determine the frequency of common mutations in African Americans with CF from the southeastern United States. delta F508 was found on 50% of CF chromosomes; 46% of CF mutations were undetermined mutations. Our data indicate that at the current detection rate, the sensitivity of CF screening in African Americans would be appreciably lower than that of whites, and thus their inclusion in screening programs probably would not be warranted.
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Lipoprotein phenotypes total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), and triglyceride levels were obtained from blood samples of 189 patients attending the Drew Hamilton Clinic in Central Harlem, New York, between 1987 and 1988. The study population ranged in age from 7 to 88 years; 135 of the patients were females and 54 were males. A difference in distribution of lipoprotein phenotypes was observed compared with the general population of the United States. ⋯ Differences also were observed for blacks versus the general US population for Type IV (24% versus 45%), Type IIB (9% versus 40%), and Type V (0% versus 5%). Types I and III were rare in both groups (0% versus < 1%). The increased frequency of Type IIA among this predominantly black inner-city population may have implications for treatment strategies and prognostic value for predicting the risk of coronary heart disease.
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Several observations seem pertinent when previous work is combined with the present investigation. The intermixture of the black and white races in the United States is an ongoing, continuous phenomenon. ⋯ The concept of the time at which the Duffy blood proteins of the African black was entirely Fy should probably be extended backward to an earlier date. Calculations to derive a completely negative Fy frequency should be cushioned by the fact that intermixture of the Caucasoid and black races took place before the onset of the slave trade.