An association between lactose intolerance and anthropometric variables in the Sudanese Shagia tribe (East Africa)

Abstract

Background: The culture of contemporary Sudanese tribes is not homogeneous. One of the three main tribes in northern Sudan is the Shagia tribe. This study is part of the large-scale research project to anthropologically and genetically describe the Shagia population, who inhabited three villages in an isolated region of the Fourth Nile Cataract. This population is extremely homogeneous as a result of geographical, genetic and cultural isolation.

Aim: The aim of the study was to analyse the frequency of two single nucleotide polymorphisms (SNPs), C/T-13910 and G/C-14010, within the isolated population. These SNPs are closely associated with lactase persistence. In addition, this study has correlated the SNPs with anthropometric measurements.

Subjects and methods: Buccal swabs were collected from 126 subjects. The DNA was extracted and the occurrence of the two alleles at each SNP was analysed using real-time PCR. An anthropometric examination of 64 adult individuals was used for an analysis of body measurements and proportions.

Results: At the C/T-13910 SNP, the CT genotype frequency was 3.2%, whilst 96.8% of individuals were homozygous for the C allele. The presence of the T allele showed a strong association with body mass index (BMI) and waist circumference. At the G/C-14010 locus, all the examined subjects were homozygous for the G allele.

Conclusions: The C/T-13910 polymorphism correlated with anthropometric measurements. Identification of the T allele of C/T-13910, in this isolated tribe, may be linked to their previously nomadic lifestyle and could provide important information on the ancestry of the tribe and the admixture of European genes.

• 4th Nile Cataract region
• lactase intolerance
• RT-PCR
• Sudan

Acknowledgements

The authors wish to thank Henryk Paner, the director of the Archaeological Museum in Gdansk, for the opportunity to conduct research in the region of the 4th Nile Cataract, and also Mahmoud el Tayeb and the entire Shagia tribe for the support and kindness. In addition, we would like to express our gratitude to the reviewer of this paper for valuable comments and suggestions.