Human Genetics

, Volume 57, Issue 3, pp 279–281

Distribution of the lactase phenotypes in the population of the Democratic Republic of the Sudan


  • R. A. L. Bayoumi
    • Department of Biochemistry, Faculty of MedicineUniversity of Khartoum
  • N. Saha
    • Department of Physiology, Faculty of MedicineUniversity of Khartoum
  • A. S. Salih
    • Military Hospital
  • A. E. Bakkar
    • Military Hospital
  • G. Flatz
    • Abteilung Humangenetik, Zentrum für Kinderheilkunde und HumangenetikMedizinische Hochschule Hannover
Original Investigations

DOI: 10.1007/BF00278944

Cite this article as:
Bayoumi, R.A.L., Saha, N., Salih, A.S. et al. Hum Genet (1981) 57: 279. doi:10.1007/BF00278944


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.

Copyright information

© Springer-Verlag 1981