Cleft Lip and Palate Etiology
In most cases the cleft lip and palate is an isolated finding where the child has no other manifestations. Many occur sporadic meaning that there are no other family members with the phenotype. It is believed that the etiology behind most of these sporadic isolated cases is a combination of environmental factors and a number of genes with a small contributing effect. We call this multifactorial inheritance. A cleft lip and palate malformation can be treated surgically in early childhood. The recurrence risk (the risk of cleft lip and palate in a sibling) is increased (2-4%) because siblings share some environmental and some genetic factors.
In some families more than one has cleft lip and palate and in some cases the cleft lip and palate is part of a syndrome meaning that the child has other manifestations. In these cases, you should consider a monogenic or chromosomal etiology. The monogenic diseases with cleft lip and palate include autosomal dominant diseases (e.g. Van der Woude syndrome), autosomal recessive diseases (e.g. Smith–Lemli–Opitz syndrome) and X-linked inherited diseases (e.g. Orofaciodigital syndrome I). Cleft lip and palate can also be one of several manifestations in numerical chromosome disorders (e.g. Trisomy 13 and Trisomy 18), in microdeletion syndromes (e.g. 22q11 deletion syndrome) and in unique unbalanced chromosome disorders. If a genetic etiology is found, you will be able to counsel the parents about the recurrence risk. If the mutation is identified, the parents can be offered prenatal genetic testing in a future pregnancy.