~4% The cited recurrence for a couple with one kid with cleft palate is 4%. Of interest , any pregnancy has ~4% risk of some unexpected outcome (inclusive of such things as prematurity, cp, etc.) this must be added to the specific risk. A counseling session with a geneticist may uncover other risks for a couple and or remove some existing fears.
4-10% The risk for siblings born of unaffected parents increase from 4% after 1 affected child, to 10% after 2 affected children (curtis 1961). If 1 parent is affected, the risk to further children after 1 affected child is around 10%. Jorde 1995 calculated the risks to first, second, and third degree relatives as 4%, .7%, and .3%. Extent of lip defect, familial history, are significant predictors.