The ABO, MN and Rh blood types, and the Hp, Tf, and Gm [Gm (a), Gm (x), Gm(b), and Gm-like] factors were determined for 128 unrelated Indians (parents of families, 63 with two parents tested and two with one parent tested), and 90 unrelated Chinese (parents of 46 families, 44 with two parents tested and two with one parent tested), and for the offspring from these families. The frequencies of the several blood types are presented. They were done primarily to aid in paternity testing. They compare favorably with the findings of previous studies. The allele Hp1 is rare in the Indian population (.09) and relatively infrequent in the Chinese (.29). Unfortunately, the data shed no light on the problem of the inheritance of the phenotype Hp O. Only Tf C was found among the Indians. About four per cent of the Chinese were heterozygous for Tf CD,, all other were Tf CC. The Indians have a high frequency of Gm(a) and of Gm (x), and a low frequency of Gm (b). They appear to have alleles Gma, Gmax, and Gmb in the following frequencies: .535, .234(5), and .230(5), respectively. Three families appear to have a GMxb allele, providing the offspring are not extra-marital. The Chinese appear to have the alleles Gm^ab, Gm^a, and Gm^ax in the following frequencies: .741, .231, and .028, respectively.
Matched MeSH terms: Blood Group Antigens/genetics*; Genetics, Population*
In a survey of over 1,000 patients with leprosy, 47 cases ( 4.4 per cent) were found to have glucose-6-phosphate dehydrogenase deficiency. A controlled clinical study suggests that such a deficiency does not modify the overall response to therapy but may predispose to a greater tendency to leprosy reactions. All patients were receiving 600 to 800 mgm. of sulphone per week and none had a frank haemolytic anaemia.
The particular agricultural adaptation we have been considering is the ultimate determinant of the presence of malaria parasites in the intracellular environment of the human red blood cell. This change in the cellular environment is deleterious for normal individuals, but individuals with the sickle-cell gene are capable of changing their red-cell environment so that intense parasitism never develops. Normal individuals suffer higher mortality rates and lower fertility rates in a malarious environment than individuals with the sickle-cell trait do, so the latter contribute proportionately more people to succeeding generations.
The yellow fever mosquito Aedes aegypti has developed resistance to DDT in the Caribbean region and in South-East Asia, but not in West Africa. Therefore West African strains were compared with South-East Asian strains for their response to laboratory selection with DDT. It was found that West African strains were much slower to respond initially, but eventually could build up a high degree of DDT-resistance. By crossing and backcrossing with a susceptible marker-gene strain, it was found that this resistance was due to a single gene linked with the gene y (yellow) on chromosome 2 at a cross-over distance of approximately 35 units in an Upper Volta strain as in a Bangkok strain; interstrain crosses indicated that the gene was the same as that in a Trinidad strain and in one from Penang. Dieldrin-resistance could be readily induced in the Upper Volta strain and proved to be due to a gene also linked with y but at a crossover distance of approximately 25 units, comparable to that in Caribbean strains previously studied. Material from Karachi, West Pakistan, developed a dieldrin-resistance also showing 25% crossing over with y, and a DDT-resistance also linked with this chromosome-2 marker gene.