A high rate of marriage among deaf individuals can explain the increased frequency of connexin deafness in the United States. The article highlights the importance of assortive mating, as it notes that “85 percent of individuals with profound deafness marry another deaf person.” So the result of this is that though the frequency of this particular recessive allele within the total population might not have increased, you no longer have a random mating population, and the frequency of recessive homozygotes is increasing (possibly).
Posted by razib at 03:24 PM