Cleft uvula: prevalence and genetics.

The prevalence of cleft uvula (CU) was determined among 70,359 school children 6-18 years of age; 90 children having the condition were chosen as probands for a family study. Prevalence of CU was 0.44 per cent with no sex differences. The Non-Ashkenazi group had a higher prevalence than the other population groups. The prevalence of CU in parents and siblings was 7.7 per cent and 7.5 per cent respectively. The findings from the family study support the hypothesis of a polygenic mode of inheritance for CU. The prevalence of cleft palate and agenesis of upper lateral incisors in the families studied did not differ from that expected in the general population.