944 adenosine deaminase phenotypings of Malay, Chinese, and Indian blood donors and newborns at Kuala Lumpur, Malaysia, yielded ADA1 gene frequency estimates of 0.885 for the Malays, 0.939 for the Chinese, and 0.853 for the Indians.
The jungle habitat of the Temuan aborigines harbors a variety of infectious diseases, the most notable being malaria. Our study of 15 genetic systems in the Temuan revealed substantial polymorphism and within-population genetic diversity. The polymorphisms for Hb beta, G6PD, and El are of interest in regard to genetic adaptation to malaria. Among the polymorphisms investigated we conclude that G6PD deficiency and elliptocytosis are likely to have malaria-resistant effects as evidenced by their low association with malarial parasitemia or their higher frequency in adults than in children. These findings suggest that the malarial habitat of the Temuans is livable in the long range sense for them because of the cluster of malaria-resistant alleles in their gene pool (G6PD)-, El, and possibly, but not tested here because of its low frequency, Hb beta E). The same condition probably holds for the Semai, the nearest aborigine neighbors of the Temuan (although the Semai have not been tested for malarial parasitemia and for these polymorphisms simultaneously), since the Semai have substantial Hb betaE, G6PD-, and El. The Temuan have a cultural identity system of rituals, beliefs, and certain aspects of language which effectively isolates them genetically from Malays and other nonaborigines. This system hinders the dilution of the malaria-resistant alleles of the Temuan gene pool with the malaria-susceptible alleles of the nonaborigine gene pools.
812 West Malaysian Orang Asli belonging to four ethnic groups were surveyed for adenosine deaminase (ADA; EC 3.5.4.4) using starch gel electrophoresis. Only the common ADA1 and ADA2 alleles were found, with the frequencies of the latter being 0.025, 0.103, 0.115 and 0.028 in the Semai, Semelai, Temuan, and Jakun groups, respectively. A new 'breeding genetic distance' was applied to these gene frequencies and the Semelai and Temuan were found to be more closely related to each other, and to have considerably more evolutionary flexibility on this scale of 'micro-evolution' than the other two groups. The Semai and Jakun were more similar to each other on the basis of these ADA gene frequencies.