Oto-palato-digital syndrome

Melnick-Needles syndrome.^[2]

craniofacial syndromes as a whole.^[3] Hand defects are particularly associated.^[2] Of the conditions, OPD1 has the milder phenotype, with normal intelligence and modestly reduced stature.^[2] In OPD2, the characteristic facial features are more severe and intellectual disability frequent; most OPD2 cases in males are stillborn or die during infancy.^[1][2] As an X-linked recessive disorder, both forms are generally more severe in males, who have one X chromosome, than females, who have two.^[4] Reports from patients of their experiences demonstrate a broad spectrum of symptom severity, including within families,^[5] which has also been reported in the medical literature.^[6]

gain-of-function mutation in the FLNA gene on the X chromosome.^[1] Women with one copy of the mutation will with each pregnancy have a 50% chance of passing it down to each child.^[7] Men with one copy of the mutation will pass it down to all daughters, and will not pass the mutation down to sons.^[1] Germline mosaicism for OPD1 has been reported, meaning that unaffected parents with an affected child have a slightly increased risk of bearing another.^[2]