April 8, 2005
Cleft lip and/or palate remains one of the most common birth defects in the world. It occurs when the sides of the face fuse abnormally in a developing baby, resulting in a malformed lip and/or roof of the mouth. Although clefts can be repaired to varying degrees with multiple surgeries, researchers have long pursued a more detailed understanding of the developmental process to learn how to prevent the condition or more efficiently treat it. Toward this end, scientists have compiled a growing list of genes and their protein products that, when altered, play a role in causing clefts. In the March 15 issue of the journal Development, NIDCR grantees and colleagues report the discovery of two genes that are likely to be involved in human clefting. The genes are: Bmp4, a member of the so-called bone morphogenetic protein (Bmp) family that regulate intercellular communication during fetal development, and Bmpr1a, the receptor for the Bmp4 protein. The scientists also report that Bmp signaling in general has distinct functions in forming the lip and secondary palate. In the lip, the Bmp signaling seems to act as a survival signal to influence the timing of programmed cell death. In the secondary palate, Bmp signaling regulates the proliferative capacity of cells that are destined to form the roof of the mouth.