Mendelian inheritance of isolated nonsyndromic cleft palate.

Isolated, apparently nonsyndromic cleft palate (CP) is thought to be etiologically heterogeneous. The multifactorial threshold explanation for CP is postulated in most cases. Mendelian inheritance has been documented in 3 families. We report on three unrelated white families with 17 relatives in several generations affected with CP, including submucous CP and bifid/absent uvula. We could find no evidence of a cleft syndrome. In one family, the pattern is consistent with autosomal dominant inheritance. In 2 families, the pattern is consistent with X-linked recessive inheritance. The specific findings and their implications for family evaluation and genetic counseling are discussed.