Résumé
Despite the importance of behavioural and environmental risk factors, there are arguments consistent with the existence of a genetic susceptibility to human African trypanosomiasis (HAT). A candidate gene association study was conducted in the Democratic Republic of Congo using a family-based sample which included a total of 353 subjects (86 trios; one case and parents (
n
=
258) and 23 families with more than one case and parents (
n
=
95)). Polymorphisms located on the
IL1α,
IL4,
IL6,
IL8,
IL10,
TNFα and
IFNγ genes were genotyped after re-sequencing of the genes for extensive SNP search. The T allele of the
IL6
4339 SNP was significantly associated with a decreased risk of developing the disease (
p
=
0.0006) and a suggestive association was observed for the
IL1α
5417 T SNP and an increased risk of developing the disease. These results suggest that genetic variability of the
IL6 and to a lesser extent the
IL1α gene are involved in the development of HAT. For the
TNFα and
IL10 gene polymorphisms, association results obtained here were different from those we observed in another population living under different epidemiologic conditions. This underlines the complexity of the interactions existing between host genetic polymorphisms, parasite diversity and behavioural and environmental risk factors in HAT.