Lactase persistence genotypes and malaria susceptibility in Fulani of Mali

Malaria Journal

Research

A Inkeri Lokki¹  Ville Holmberg²  Seppo Meri³  Ogobara K Doumbo⁴  Amagana Dolo⁴  Marita Troye-Blomberg⁵  Bakary Maiga⁶  Irma Järvelä⁷  Elisabeth Israelsson⁸ 

[1] Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, P.O. Box 21, FIN-00014, Finland;Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, P.O. Box 21, FIN-00014, Finland;Division of Infectious Diseases, Department of Medicine, Helsinki University Central Hospital, Helsinki, Finland;Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, P.O. Box 21, FIN-00014, Finland;Laboratory Services, Helsinki University Central Hospital, Helsinki, Finland;Department of Epidemiology of Parasitics Diseases, Malaria Research & Training Center, Faculty of Medicine, Pharmacy & Odonto Stomatology, University of Bamako, Bamako, Mali;Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, Sweden;Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, Sweden;Department of Epidemiology of Parasitics Diseases, Malaria Research & Training Center, Faculty of Medicine, Pharmacy & Odonto Stomatology, University of Bamako, Bamako, Mali;Department of Medical Genetics, University of Helsinki, Helsinki, Finland;Laboratory Services, Helsinki University Central Hospital, Helsinki, Finland;Seattle Biomedical Research Institute, Seattle, USA;Department of Immunology, Wenner-Gren Institute, Stockholm University, Stockholm, Sweden;

关键词: Malaria;    Malaria Infection;    Severe Malaria;    Parasite Density;    Lactase;   

DOI  :  10.1186/1475-2875-10-9

 received in 2010-09-24, accepted in 2011-01-14,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundFulani are a widely spread African ethnic group characterized by lower susceptibility to Plasmodium falciparum, clinical malaria morbidity and higher rate of lactase persistence compared to sympatric tribes. Lactase non-persistence, often called lactose intolerance, is the normal condition where lactase activity in the intestinal wall declines after weaning. Lactase persistence, common in Europe, and in certain African people with traditions of raising cattle, is caused by polymorphisms in the enhancer region approximately 14 kb upstream of the lactase gene.MethodsTo evaluate the relationship between malaria and lactase persistence genotypes, a 400 bp region surrounding the main European C/T-13910 polymorphism upstream of the lactase gene was sequenced. DNA samples used in the study originated from 162 Fulani and 79 Dogon individuals from Mali.ResultsAmong 79 Dogon only one heterozygote of the lactase enhancer polymorphism was detected, whereas all others were homozygous for the ancestral C allele. Among the Fulani, the main European polymorphism at locus C/T-13910 was by far the most common polymorphism, with an allele frequency of 37%. Three other single-nucleotide polymorphisms were found with allele frequencies of 3.7%, 1.9% and 0.6% each. The novel DNA polymorphism T/C-13906 was seen in six heterozygous Fulani. Among the Fulani with lactase non-persistence CC genotypes at the C/T-13910 locus, 24% had malaria parasites detectable by microscopy compared to 18% for lactase persistent genotypes (P = 0.29). Pooling the lactase enhancer polymorphisms to a common presumptive genotype gave 28% microscopy positives for non-persistent and 17% for others (P = 0.11).ConclusionsPlasmodium falciparum parasitaemia in asymptomatic Fulani is more common in individuals with lactase non-persistence genotypes, but this difference is not statistically significant. The potential immunoprotective properties of dietary cow milk as a reason for the partial malaria resistance of Fulani warrant further investigation.

【 授权许可】

CC BY   
© Lokki et al; licensee BioMed Central Ltd. 2011