Syndromic and non-syndromic orofacial clefts

Orofacial clefts are the second most common congenital malformation. The two frequent subgroups are the cleft lip with or without cleft palate and the isolated cleft palate. Both can be part of a wide variety of syndromes. Cleft lip with or without cleft palate is more often non-syndromic (70%) compared to cleft palate (50%). Non-syndromic clefts aremultifactorial and recurrence risks for relatives are relatively low. Some of the syndromic clefts result from chromosomal abnormalities but the vast majority are monogenic. The autosomal dominant Van der Woude syndrome is an important differential diagnosis for non-syndromic clefts. It can only be distinguished from non-syndromic clefts by lower lip pits and carries a higher risk for clefts in subsequent generations. The prenatal diagnostics of orofacial clefts are performed by ultrasound. Experienced examiners are able to identify cleft lip with or without cleft palate from the 20th week of pregnancy. Prenatal detection of a cleft palate, however, remains a challenge.