Congenital bilateral absence of the vas deferens and recombination at CFTR.

摘要

Pompei et al report a paucity of variation on V470 haplotypes at the CFTR locus relative to M470 haplotypes on unselected chromosomes from the general population. A conservative estimate of the region of 'extended haplotype homozygosity' that they report would extend from I148T (29 kb 5' of V470) to S123SR (68 kb 3' of V470). The authors suggest that this pattern could be explained by a recent increase of the V470 variant to high frequency, either by natural selection for V470 itself or for another, linked variant in cis. In this scenario, V470 haplotypes are depauperate for sequence variation because they have had little time to accumulate variation due to mutation or by recombination with M470 haplotypes.