interferon regulatory factor 6
The IRF6 gene provides instructions for making a protein that plays an important role in early development. This protein is a transcription factor, which means that it attaches (binds) to specific regions of DNA and helps control the activity of particular genes.
The IRF6 protein is active in cells that give rise to tissues in the head and face. It is also involved in the development of other parts of the body, including the skin and genitals.
Mutations in the IRF6 gene that cause popliteal pterygium syndrome may change the transcription factor's effects on the activity of certain genes. This affects the development and maturation of tissues in the face, skin, and genitals, resulting in the facial and genital abnormalities, skin webbing, and fusion of the fingers or toes (syndactyly) seen in popliteal pterygium syndrome.
Mutations in the IRF6 gene that cause van der Woude syndrome prevent one copy of the gene in each cell from making any functional protein. A shortage of the IRF6 protein affects the development and maturation of tissues in the skull and face. These abnormalities underlie the signs and symptoms of van der Woude syndrome, including cleft lip, cleft palate (an opening in the roof of the mouth), and pits or mounds in the lower lip.
Certain variations in the IRF6 gene have been associated with increased risk of cleft lip, cleft palate, or both. When these features appear without other signs or symptoms, the condition is called isolated cleft lip and/or palate. The IRF6 gene variations are believed to affect the function of the IRF6 protein in its role as a transcription factor, which may interfere with the normal development of the face.