Incidence of cleft lip and palate in Sri Lanka.

In a prospective study that surveyed 51,542 live births and 5,263 still births in central Sri Lanka, cleft lip with or without cleft palate (CL +/- P) was found to have an incidence of 0.83 per 1,000 births, and isolated cleft palate (CP) an incidence of 0.19 per 1,000 births. Distribution by sex, type of cleft, and site was similar to that in whites. Family history was positive in 19.6% of CL +/- P and in 9.1% of CP subjects. Furthermore, the frequency of CL +/- P in relatives of subjects with CL +/- P was significantly greater than that of CP. Of the three major ethnic groups that inhabit Sri Lanka, the incidence was significantly greater in the Moors than in the Sinhalese and the Tamils. Social status was found to have no association with the occurrence of clefts.