Transcription factor involved in skull and limb development. Plays an essential role in craniofacial development, skin and hair follicle development. Defects in ALX4 are the cause of parietal foramina 2 (PFM2); also known as foramina parietalia permagna (FPP). PFM2 is an autosomal dominant disease characterized by oval defects of the parietal bones caused by deficient ossification around the parietal notch, which is normally obliterated during the fifth fetal month. PFM2 is also a clinical feature of Potocki- Shaffer syndrome. Defects in ALX4 are the cause of frontonasal dysplasia type 2 (FND2). The term frontonasal dysplasia describes an array of abnormalities affecting the eyes, forehead and nose and linked to midfacial dysraphia. The clinical picture is highly variable. Major findings include true ocular hypertelorism; broadening of the nasal root; median facial cleft affecting the nose and/or upper lip and palate; unilateral or bilateral clefting of the alae nasi; lack of formation of the nasal tip; anterior cranium bifidum occultum; a V-shaped or widow's peak frontal hairline. Defects in ALX4 are a cause of Potocki-Shaffer syndrome (POSHS). A contiguous gene syndrome caused by deletion of the 11p11.2 region. Belongs to the paired homeobox family. Note: This description may include information from UniProtKB.