What causes cleft lip & palate deformity?

These birth defects occur very early in fetal development. The tissure that will become the lip usually joins in the middle and fuses by about 5 to 6 weeks after conception. The palate forms in a similar manner at about 7 weeks. A cleft occurs when these structures do not cluse completely. The causes of these birth defects are not well understood. Studies suggest that a number of genes, as well as environmental factors, such as drugs and maternal smoking may contribute. Other environmental factors that are suspected of playing a role include infections, maternal alcohol use and deficiency of the B vitamin folic acid. Certain genes or gene mutations (changes) may cause cleft lip/palate, while others may cause isolated palate.

*information courtesy of www.marchofdimes.com