Summary
The distribution of the adult lactase phenotypes, lactose absorption, and lactose malabsorption, was determined by a field version of the hydrogen breath test for disaccharide absorption in a sample of 563 subjects residing in the Democratic Republic of the Sudan. Relatively high proportions of lactose absorption were found in the northern nomadic groups who rely heavily on dairying for their livelihood. Residential Nile valley populations revealed intermediate frequencies of the two phenotypes whereas the negroid populations of the south exhibited a high prevalence of lactose malabsorption irrespective of their economic status with respect to agriculture and dairying. The frequency of the “hypolactasia allele” ranged between 0.6 and 0.87 in the major regional groups.
Similar content being viewed by others
References
Bayless TM, Rosensweig NS (1966) A racial difference in incidence of lactase deficiency. A survey of milk intolerance and lactase deficiency in healthy adult males. JAMA 197:968–972
Cook GC (1973) Incidence and clinical features of specific hypolactasia in man. In: Borgstrom M, Dahlqvist A, Hambraeus L (eds) Intestinal enzyme deficiencies and their nutritional implications. Almqvist and Wiksell, Stockholm, p 52
Cook GC, Kajubi SK (1966) Tribal incidence of lactase deficiency in Uganda. Lancet 1:725–729
Dahlqvist A (1974) Enzyme deficiency and malabsorption of carbohydrates. In: Sipple HL, McNutt KW (eds) Sugars in nutrition. Academic Press, New York, p 187
Flatz G, Rotthauwe HW (1973) Lactose nutrition and natural selection. Lancet 2:76–77
Flatz G, Rotthauwe HW (1977) The human lactase polymorphism: Physiology and genetics of lactose absorption and malabsorption. Prog Med Genet (new series) 2:205–249
Howell JN, Schockenhoff T, Flatz G (1981) Population screening for the human adult lactase phenotypes with a multiple breaths version of the breath hydrogen test. Hum Genet 57:276–278
Johnson JD, Kretchmer N, Simoons FJ (1974) Lactose malabsorption: Its biology and history. Adv Pediatr 21:197–237
Levitt MD, Donaldson RM (1970) Use of respiratory hydrogen (H2) excretion to detect carbohydrate malabsorption. J Lab Clin Med 75:937–945
McCracken RD (1971) Lactase deficiency: An example of dietary evolution. Curr Anthropol 12:479–500
Sahi T, Isokoski M, Jussila J, Launiala K, Pyöräla K (1973) Recessive inheritance of adult type lactose malabsorption. Lancet 2:823–826
Shatin R (1968) Evolution and lactase deficiency. Gastroenterology 54:992
Simoons FJ (1970) Primary adult lactose intolerance and the milking habit: A problem in biologic and cultural interrelations. II. A culture historical hypothesis. Am J Dig Dis 15:695–710
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bayoumi, R.A.L., Saha, N., Salih, A.S. et al. Distribution of the lactase phenotypes in the population of the Democratic Republic of the Sudan. Hum Genet 57, 279–281 (1981). https://doi.org/10.1007/BF00278944
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00278944