ALX homeobox 3
The ALX3 gene provides instructions for making a protein that is a member of the homeobox protein family. Homeobox proteins direct the formation of body structures during early embryonic development. The ALX3 protein is necessary for normal development of the head and face, particularly the formation of the nose, which begins around the fourth week of development. The ALX3 protein is a transcription factor, which means that it attaches (binds) to DNA and controls the activity of certain genes. Specifically, the protein controls the activity of genes that regulate cell growth and division (proliferation) and movement (migration), ensuring that cells grow and stop growing at specific times and that they are positioned correctly during development.
At least seven mutations in the ALX3 gene have been found to cause frontonasal dysplasia. ALX3 gene mutations cause a form of the disorder called frontonasal dysplasia type 1, which particularly affects the development of the nose and surrounding tissues. ALX3 gene mutations that cause this condition severely reduce or eliminate the function of the ALX3 protein. As a result, the protein cannot bind to DNA and regulate gene function, which leads to poorly controlled cell proliferation and migration during development. This abnormal cell growth and movement impairs development of structures in the middle of the face, particularly the nose, leading to openings (clefts) in the nose. This abnormal development can also interfere with the proper formation of the skull, leading to the skull malformations typical of frontonasal dysplasia type 1.
- aristaless-like homeobox 3
- frontonasal dysplasia
- homeobox protein aristaless-like 3
- proline-rich transcription factor ALX3