Evidence for the Carter effect in atopy.
In atopy, the sex ratio deviates markedly from unity when the specific organ manifestations are considered separately. In atopic asthma, the male to female ratio is about 2:1. In the children of patients affected with atopic asthma, we determined the incidence of atopic dermatitis, atopic asthma and atopic rhinitis. Among children of women affected with atopic asthma, we found more often atopic manifestations than among children of men affected with atopic asthma (44 vs. 25.5%). This phenomenon, called the Carter effect, can be explained by the multifactorial mode of inheritance. A certain number of genes is necessary for clinical signs of atopy to become manifest. Women with atopic asthma have a higher threshold and therefore transmit more predisposing genes to their children. This demonstration of the Carter effect is a further argument in favor of polygenic inheritance of atopy.
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000235:genetics; D003876:Dermatitis, Atopic / Q000235:genetics; D005260:Female; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000235:genetics*; D007223:Infant; D008297:Male; D012221:Rhinitis, Allergic, Perennial / Q000235:genetics; D012744:Sex Ratio