My brother was born with a cleft lip/palate but i was not. is this hereditary?

Multifactorial: The complete answer is not understood. Genetics, environment ethnicity and nutrition do play a part.

Sporadic event: Clcp defects occur sporadically in the population. The cause is unknown but there are a complex series of genes involved. A clcp parent has a 4% risk of a second child with the defect, & 2 clcp parents have about 8% risk of a child with a defect. Most occur in families with no history of prior defects.

Yes: If the parent is unaffected, the risk is at 4% after 1 affected child. If one parent is affected, the risk is at 10% after one affected child. Mitchell and risch, 1993 found that the severity of the proband's defect (the extent of lip defect as opposed to palatal involvement) was a significant predictor of sibbling recurrence. A positive family history also a significant predictor.