Brachydactyly type A1

Alternate names

BDA1; Brachydactyly Farabee type

Definition

Brachydactyly type A1 (BDA1) is a congenital malformation characterized by apparent shortness (or absence) of the middle phalanges of all digits, and occasional fusion with the terminal phalanges.

Epidemiology

Only a few pedigrees have been reported in the literature.

Cause

BDA1 may be caused by mutations in the Indian hedgehog gene (IHH) located on chromosome 2q35-36. Another locus for this phenotype has been identified on chromosome 5p13.3-p13.2.

Inheritance

Autosomal dominant pattern, a 50/50 chance.

BDA1 is inherited as an autosomal dominant trait.

Signs and symptoms

The proximal phalanges of the thumbs and big toes are short. BDA1 patients tend to be of short stature in adulthood.

For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed.

80%-99% of people have these symptoms

• Short foot(Short feet)
• Short hallux(Short big toe)
• Short middle phalanx of finger(Short middle bone of finger)
• Short stature(Decreased body height)
• Short thumb(Short thumbs)

30%-79% of people have these symptoms

• Cone-shaped epiphysis(Cone-shaped end part of bone)

5%-29% of people have these symptoms

• Broad metacarpals(Wide long bones of hand)
• Clinodactyly of the 5th finger(Permanent curving of the pinkie finger)
• Distal symphalangism of hands(Fused outermost bones of hand)
• Hypoplasia of the ulna(Underdeveloped inner large forearm bone)
• Scoliosis
• Talipes equinovarus(Club feet)

NIH genetic and rare disease info

• NIH info on Brachydactyly type A1

Brachydactyly type A1 is a rare disease.

This article is a stub. You can help WikiMD by registering to expand it. Editing is available only to registered and verified users. WikiMD is a comprehensive, free health & wellness encyclopedia.