Some blood genetic markers of the Nuba and Hawazma tribes of Western Sudan

Abstract

Two hundred eighty subjects comprising 112 Nuba and 168 Hawazma of the Sudan were tested for the distribution of hemoglobins, eight red cell enzymes, and four serum proteins. The Nuba, the indigenous negroid tribe, had no HbS, HbO-Arab, or GdB(Khartoum) compared to the Hawazma tribe of Negro-Arab descent. The gene frequencies of the above polymorphic systems in the latter were as follows: HbS, 0.13; HbO-Arab, 0.01; GdB(Khartoum), 0.03. The frequency of GdA was higher in the Hawazma than in the Nuba. A high frequency of glucose 6-phosphate dehydrogenase (G6PD) deficiency and HpO was present in both the tribes. Essentially similar gene frequencies of Hp1, TfD, PGDC, pC, and PGM1 were observed in both Nuba and Hawazma. The average heterozygosity at five polymorphic loci was the same (0.23) in both the tribes. The above results agree with the social practice whereby people of mixed Hawazma and Nuba descent are considered members of the Hawazma tribe and confirm that racial admixture between the two groups can be seen as a process of gene flow from the Nuba to the Hawazma, even though the Nuba are the indigenous group, while the Hawazma are the new settlers.

Inbreeding effects on average heterozygosity in the Sudan

“…This is also consistent with the lack of inbreeding effects on the reproductive profiles observed in the Sudanese and South Indian populations and the lack of expected deviation from the HardyWeinberg equilibrium in the phenotypic distribution of blood genetic markers in several earlier studies in the Sudanese population (Saha et al, 1978(Saha et al, , 1979Bayoumi et al, 1985;Bayoumi and Saha, 1987).…”

“…Similarly, we failed to observe any significant effects of inbreeding on reproductive outcome in a Sudanese population inspite of the high degree of inbreeding practised by the population El Sheikh, 1987, Saha et al, 1989). This is further substantiated by the finding of a lack of deviation from the Hardy-Weinberg equilibrium in the phenotypic distribution of many polymorphic loci at least in three of our earlier studies on population genetics in the Sudan (Saha et al, 1978(Saha et al, , 1979Bayoumi et al, 1985;Bayoumi and Saha, 1987).…”

Inbreeding Effects on Reproductive Outcome in a Sudanese Population

“…The lack of any demonstrable effects of inbreeding on fer tility and morbidity in the highly inbred population of the Sudan can be explained by the long practice of a high level of inbreeding in the population. This has prob ably slowly eliminated the deleterious homozygotes in earlier generations from the population, as suggested by MacCluer [1980] and Sanghvi [1982], This is further substantiated by (1) a lack of deviation from the Hardy-Weinberg equilibrium in the phenotypic distriubtion of many poly morphisms so far studied in the Sudanese population [Laha et al ., 1979;Saha et al, 1978Saha et al, , 1979Bayoumi et al, 1985;Bayoumi and Saha, 1987], and (2) an absence of significant difference in average heterozy gosity between the inbred and outbred populations [Saha et al, unpubl. data].…”

Relationship of the Sickle Cell Gene to the Ethnic and Geographic Groups Populating the Sudan

“…The Bergu, Fur and Masalit had the highest frequencies of the S gene among the rather ‘indigenous’ Sudanese Nilo-Saharan-speaking groups. The fact that they mostly harbor West African haplotypes and the geographic locations of these tribes make it safe to assume a gene flow through genetic admixture with populations from West Africa, as proposed by Bayoumi and Taha [30 ]and Bayoumi and Saha [31]. …”