Cystic fibrosis allele frequency, sex ratio anomalies and fertility: a new theory for the dissemination of mutant alleles.
The observation that mothers of cystic fibrosis patients come from sibships that are larger than those of the fathers is explained by a decrease in sex ratio with increasing size of parental sibships. This feature also provides the basis for a new theory for the dissemination of the major mutant allele, deduced to have arisen 2,700-5,000 years ago, in accordance with an overall heterozygote advantage of around 3%. In heterozygous women with heterozygous partners, sex-related selection probably occurs after fertilization.
Division of Human Genetics, School of Pathological Sciences, Newcastle upon Tyne, UK.
D J
DJ
Pritchard
D000483:Alleles; D003550:Cystic Fibrosis / Q000235:genetics*; D005260:Female; D005298:Fertility; D005787:Gene Frequency; D006801:Humans; D008297:Male; D009154:Mutation; D012744:Sex Ratio