Cleft lip with or without cleft palate: identification of sporadic cases with a high level of genetic predisposition.

Previous studies have suggested that asymmetry for certain bilaterally represented features may be an indicator of genetic predisposition to cleft lip with or without cleft palate and may therefore be of value in the individual assessment of recurrence risk, particularly for sporadic cases. An asymmetry score has been devised that may be of use in identifying those with a high level of genetic predisposition. Stepwise logistic regression selected nine variables that together correctly classified 85% of familial cleft patients and unrelated non-cleft controls. Applying the same regression equation to sporadic cases, 26% fell into the range occupied by the majority of familial patients, suggesting that these had a high level of genetic predisposition.