Heterozygote advantage in cystic fibrosis: mosquito tests.

Tests to demonstrate a preference by mosquitoes for stinging controls as opposed 
to obligate heterozygotes for Cystic Fibrosis proved negative. If a heterozygote 
advantage caused a lower malarial incidence in carriers in South West 
Africa, it must have worked through the malarial parasite being adversely 
affected by a serum factor. This remains to be tested. 