MedGen

In the classification of the brachydactylies, the analysis by Bell (1951) proved highly useful. The type A brachydactylies of Bell have the shortening confined mainly to the middle phalanges. In the brachydactyly A1 type (BDA1), the middle phalanges of all the digits are rudimentary or fused with the terminal phalanges. The proximal phalanges of the thumbs and big toes are short. Genetic Heterogeneity of Brachydactyly Type A1 BDA1B (607004) has been mapped to chromosome 5. BDA1C (615072) is caused by mutation in the GDF5 gene (601146) on chromosome 20q11. BDA1D (616849) is caused by mutation in the BMPR1B gene (603248) on chromosome 4q22. [from OMIM]

Autosomal dominant spastic paraplegia-9A is a neurologic disorder characterized by onset of slowly progressive spasticity mainly affecting the lower limbs. The age at onset usually ranges from adolescence to adulthood, and patients have gait difficulties, motor neuropathy, and dysarthria. Additional variable features include cerebellar signs, cataract, pes cavus, and urinary urgency (summary by Coutelier et al., 2015). For a general phenotypic description and a discussion of genetic heterogeneity of autosomal dominant spastic paraplegia, see SPG3A (182600). [from OMIM]

Eiken syndrome (EKNS) is an autosomal recessive skeletal dysplasia characterized by delayed ossification of bones, epiphyseal dysplasia, and bone remodeling abnormalities. Type A1 brachydactyly (see 112500), supernumerary epiphyses of proximal phalanges and metacarpals, and failure of eruption of primary teeth have also been described. Defining radiologic features include delayed ossification of epiphyses and primary ossification centers of short tubular bones, modeling abnormalities of tubular bones, and angel-shaped phalanges (Jacob et al., 2019). See 603740 for a disorder with similar radiologic features. [from OMIM]

An extremely rare syndrome with characteristics of the association of radioulnar synostosis with microcephaly, scoliosis, short stature and intellectual deficit. [from SNOMEDCT_US]