Is oral-facial-digital syndrome inherited ?
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.  In males (who have only one X chromosome), mutations result in a total loss of the OFD1 protein. A lack of this protein is usually lethal very early in development, so very few males are born with oral-facial-digital syndrome type I. Affected males usually die before birth, although a few have lived into early infancy.  Most of the other forms of oral-facial-digital syndrome are inherited in an autosomal recessive pattern, which suggests that both copies of a causative gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.