Oral-facial-digital syndrome is actually a group of related conditions that affect the development of the oral cavity (the mouth and teeth), facial features, and digits (fingers and toes).
Only one gene, OFD1, has been associated with oral-facial-digital syndrome. Mutations in this gene cause oral-facial-digital syndrome type I. OFD1 gene mutations were also found in an affected family whose disorder was classified as type VII; however, researchers now believe that type VII is the same as type I.
Oral-facial-digital syndrome has an estimated incidence of 1 in 50,000 to 250,000 newborns. Type I accounts for the majority of cases of this disorder. The other forms of oral-facial-digital syndrome are very rare; most have been identified in only one or a few families.
Oral-facial-digital syndrome type I is inherited in an X-linked dominant pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In females (who have two X chromosomes), a mutation in one of the two copies of the gene in each cell is sufficient to cause the disorder. Some cells produce a normal amount of OFD1 protein and other cells produce none. The resulting overall reduction in the amount of this protein leads to the signs and symptoms of oral-facial-digital syndrome type I.
Published Date: February 01, 2010Published By: National Institutes of Health