OMIM ID:
Barber-Say Syndrome
Alternate Names
Defective Genes
Clinical Characteristics
Ocular Features
The ocular features consist mainly of skin changes in the lids including hyperlaxity and redundancy. There may be ectropion of the lower eyelids and sparsity of the eyebrows. Some evidence of micro- or ablepharon is often present. Hypertelorism and exophthalmia have been described.
Systemic Features
Multiple external congenital anomalies are present at birth including skin laxity, hypertrichosis (especially of the forehead, neck and back), and low-set and malformed pinnae. Macrostomia and thin lips with redundant facial skin are often evident. The nose appears bulbous. The thoracic skin can be atrophic and the nipples may be hypoplastic. Hypospadias has been reported. A highly arched or cleft palate may be present and some individuals have a conductive hearing loss. The teeth are small and eruption may be delayed. Cognitive deficits may be present and mental retardation has been reported.
Genetics
Inheritance
Based on genotyping and the limited number of reported pedigrees, inheritance most likely follows an autosomal dominant pattern. Direct parent to child transmission has been reported. Detailed examination of parents sometimes reveals mild features that are easily missed. Mutations in the TWIST2 gene have been found in 10 unrelated individuals with Barber-Say syndrome.
TWIST2 mutations have also been found in Setleis syndrome (227260) and in ablepharon-macrostomia syndrome (200110). These conditions have some clinical features in common with Barber-Say syndrome.
Pedigree
Autosomal dominant
Autosomal dominant disorders require only one mutation for the disease to be expressed. Since an affected parent has two chromosomes, only one of which has the mutant gene, parents can expect that half (50%) of their children will receive that one and inherit the disease. It is common for individuals that inherit the mutation, however, to not have evidence of the disease (nonpenetrance).
Autosomal dominant inheritance leads to a vertical pattern of transmission