Cleft lip and cleft palate in Iceland

The frequency of cleft lip and cleft palate in Iceland was determined from surgical records, maternity journals and birth records. During the period (1956–1962) under study sixty-four children with cleft lip and/or cleft palate were born amongst 32,979 births in Iceland. This is a ratio of one affected child per 515 births, or 1.94 pro mille. 59.4 per cent of the affected children were males. The most common cleft type among the males was unilateral (left side) cleft lip with cleft palate, and the most common cleft among the females, the isolated cleft palate. Unilateral clefts were much more common than bilateral clefts, and occurred three times more on the left than on the right side.Family histories were obtained for 50 of the propositi and for 42 of a control group. Relatives with cleft defects were reported for 46.0 per cent of the propositi and 7.1 per cent of the controls. Children with cleft lip and cleft palate (Group III) showed the highest degree of familial association.Incidental observations were made on the birth months of the affected children, their degree of prematurity, their birth weights, birth order, the age of their mother, and the presence of other congenital anomalies.