Complement receptor 1 polymorphisms associated with resistance to severe malaria in Kenya.
BACKGROUND
It has been hypothesized that the African alleles Sl2 and McCb of the Swain-Langley (Sl) and McCoy (McC) blood group antigens of the complement receptor 1 (CR1) may confer a survival advantage in the setting of Plasmodium falciparum malaria, but this has not been demonstrated.


METHODS
To test this hypothesis, children in western Kenya with severe malaria-associated anaemia or cerebral malaria were matched to symptomatic uncomplicated malaria controls by age and gender. Swain-Langley and McCoy blood group alleles were determined by restriction fragment length polymorphism and conditional logistic regression was carried out.


RESULTS
No significant association was found between the African alleles and severe malaria-associated anaemia. However, children with Sl2/2 genotype were less likely to have cerebral malaria (OR = 0.17, 95% CI 0.04 to 0.72, P = 0.02) than children with Sl1/1. In particular, individuals with Sl2/2 McC(a/b) genotype were less likely to have cerebral malaria (OR = 0.18, 95% CI 0.04 to 0.77, P = 0.02) than individuals with Sl1/1 McC(a/a).


CONCLUSIONS
These results support the hypothesis that the Sl2 allele and, possibly, the McCb allele evolved in the context of malaria transmission and that in certain combinations probably confer a survival advantage on these populations.
Thathy
Vandana
V
The US Army Medical Research Unit, The Kenya Medical Research Institute, Nairobi, Kenya. vthathy@wrp-ksm.org
Moulds
JoAnn M
JM
Guyah
Bernard
B
Otieno
Walter
W
Stoute
José A
JA
D002675:Child, Preschool; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D007223:Infant; D007630:Kenya; D016015:Logistic Models; D016779:Malaria, Cerebral / Q000235:genetics; D016778:Malaria, Falciparum / Q000235:genetics*; D008297:Male; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D011951:Receptors, Complement / Q000235:genetics*; D012307:Risk Factors
D011951:Receptors, Complement