Sex ratios in otosclerotic families.

The sex ratio (proportion of males) of offspring of otosclerotics is significantly and substantially below expectation. To account for this and other features of the condition, it has been suggested elsewhere that otosclerosis is subject to autosomal dominant transmission with intrauterine selection against male heterozygotes. To test this hypothesis, a search was made for published data on the sexes of sibs of otosclerotics. These sibs do not have an unusual sex ratio, thus casting doubt on the hypothesis. Accordingly it is suggested here that both the condition and the sex ratios are causally related to levels of steroid hormones.