If parents without clefts have a child with a cleft, what is the estimated chance they will have another child with a cleft?

When considering the risk of having another child with a cleft if the parents have one child affected by clefting and they themselves do not have clefts, the estimated recurrence risk typically falls within the range of 10-20%. This is based on studies that suggest the likelihood of clefts occurring is influenced by multiple genetic and environmental factors, even when parents do not show any signs of the condition.

The initial incidence of cleft lip with or without cleft palate in the general population is roughly estimated at 1 in 1000 births. However, once a child is born with a cleft, the risk for subsequent children increases due to potential genetic predispositions or environmental factors that were not present during the first pregnancy.

The range of 10-20% is commonly cited in medical literature as it reflects a significant increase over the baseline risk while also accounting for the uncertainty and variability in genetic expression. Factors such as the specific type of cleft, family history, and broader genetic background can further influence these probabilities, but in general terms, this range is widely accepted for families without clefts having a child known to have a cleft.