Brachydactyly

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Brachydactyly
Classification and external resources
Brachydaktylia.svg
Different forms of brachydactyly
ICD-10 Q68.1
ICD-9 755.2-755.4
DiseasesDB 29782
MeSH D059327

Brachydactyly (Greek βραχύς = "short" plus δάκτυλος = "finger"), is a medical term which literally means "shortness of the fingers and toes" (digits). The shortness is relative to the length of other long bones and other parts of the body. Brachydactyly is an inherited, usually dominant trait. It most often occurs as an isolated dysmelia, but can also occur with other anomalies as part of many congenital syndromes.

Nomograms for normal values of finger length as a ratio to other body measurements have been published. In clinical genetics the most commonly used index of digit length is the dimensionless ratio of the length of the 3rd (middle) finger to the hand length. Both are expressed in the same units (centimeters, for example) and are measured in an open hand from the fingertip to the principal creases where the finger joins the palm and where the palm joins the wrist. A nomogram can be found in the Appendix of Jones, ed. Smith's Recognizable Patterns of Human Malformation, 5th edition, Philadelphia: Saunders (1997).

Types[edit]

There are several types of Brachydactyly:

Type OMIM Gene Locus Also known as/Description
Type A1, BDA1 112500 IHH BDA1B 5p13.3-p13.2, 2q33-q35 Brachydactyly type A1 or Farabee-type brachydactyly. BDA1 is an autosomal dominant inherited disease. Features include: Brachydactyly, Short or absent phalanges, Extra carpal bones, Hypoplastic or absent ulna and Short metacarpal bones.
Type A2, BDA2 112600 BMPR1B GDF5 20q11.2, 4q23-q24 Brachydactyly type A2, Brachymesophalangy II or Brachydactyly Mohr-Wriedt type. Type A2 is a very rare form of brachydactyly. The phalanges of the index fingers and second toes are shortened.
Type A3, BDA3 112700 Brachydactyly type A3, Brachymesophalangy V or Brachydactyly-Clinodactyly.
Type A4, BDA4 112800 Brachydactyly type A4, Brachymesophalangy II and V or Brachydactyly Temtamy type
Type A5, BDA5 112900 Brachydactyly type A5 nail dysplasia.
Type A6, BDA6 112910 Brachydactyly type A6 or Osebold-Remondini syndrome.
Type A7, BDA7 Brachydactyly type A7 or Brachydactyly Smorgasbord type.[1]
Type B, BDB (or BDB1) 113000 ROR2 9q22 Brachydactyly type B.
Type C, BDC 113100 GDF5 20q11.2 Brachydactyly type C or Brachydactyly Haws type.
Type D, BDD 113200 HOXD13 2q31-q32 Brachydactyly type D. Referred to colloquially as "clubbed thumbs".
Type E, BDE 113300 HOXD13 2q31-q32 Brachydactyly type E.
Type B and E 112440 ROR2 HOXD13 9q22, 2q31-q32 Brachydactyly types B and E combined, Ballard syndrome or Pitt-Williams brachydactyly.
Type A1B, BDA1B 607004 5p13.3-p13.2 Brachydactyly type A1, B.

Other syndromes[edit]

In the above brachydactyly syndromes, short digits are the most prominent of the anomalies, but in many other syndromes (Down syndrome, Rubinstein-Taybi syndrome, etc.), brachydactyly is a minor feature compared to the other anomalies or problems comprising the syndrome.

See also[edit]

References[edit]

  1. ^ Meiselman SA, Berkenstadt M, Ben-Ami T, Goodman RM (1989). "Brachydactyly type A-7 (Smorgasbord): a new entity". Clin. Genet. 35 (4): 261–7. doi:10.1111/j.1399-0004.1989.tb02940.x. PMID 2714013. 

External links[edit]