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Brachydactyly type B
Disease definition
Brachydactyly type B (BDB) is a very rare congenital malformation characterized by hypoplasia or aplasia of the terminal parts of fingers 2 to 5, with complete absence of the fingernails.
ORPHA:93383
Summary
Epidemiology
Prevalence is unknown but only a few cases have been reported in the literature.
Clinical description
The thumbs are always intact but frequently show flattening, splitting or duplication of the distal phalanges. Digits on the radial side of the hand are less severely affected than those on the ulnar side. The feet are similarly affected but less severely. Soft tissue syndactyly, symphalangism, carpal and/or tarsal fusions and shortening of metacarpals and/or metatarsals may be present.
Etiology
In the majority of cases, BDB is caused by mutations in the receptor kinase-like orphan receptor 2 gene (ROR2) on 9q22.
Genetic counseling
An autosomal dominant pattern of inheritance has been reported.
Additional information