Brachydactyly A1 - IHH gene

Brachydactyly defines a group of inherited malformations characterized by the shortening of fingers due to abnormal development of the phalanges and / or metacarpals. Brachydactyly type A1 (BDA1) is characterized by middle phalanges of all fingers rudimentary or fused with the terminal phalanges. The proximal phalanges of the thumbs are short.

This process is due to mutations in the IHH gene, located on the long arm of chromosome 2 (2q33-q35). This gene encodes a member of the "hedgehog" family of molecules secreted signaling. Proteins "hedgehog" are key regulators of a variety of developmental processes including growth, patterning and morphogenesis. Specifically, the encoded protein can regulate the balance between growth and ossification of developing bones. Mutations in this gene are the cause brachydactyly type A1 characterized by a shortening or malformation of the phalanges.

Brachydactyly type A1 (BDA1) is inherited as an autosomal dominant, which means that a copy of an altered gene in each cell is sufficient to express the disease.

Tests performed in IVAMI: in IVAMI perform detection of mutations associated with brachydactyly type A1, by complete PCR amplification of exons IHH gene, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).