Brachydactyly (BD) essentially refers to short digits. It is often inherited as an autosomal dominant trait (all the types). The clinical spectrum can widely range from minor digital hypoplasia to complete aplasia. As a group, it most commonly involves the middle phalanx 2.
Single or multiple bones of individual digits, single bones of multiple digits, or multiple bones of different digits may be involved.
Bell classification of brachydactyly
This classification was initially proposed by Bell in 1951 and further elaborated by Temtamy5 et al. in 1978, and at time of writing (July 2016) is the most widely accepted classification.
Different types of brachydactyly are classified according to their clinical and radiographic features of phalangeal or metacarpal involvement. Most widely used system is Bell's classification which delineates 5 major types (A-E) -
- type A - (brachymesophalangy)
- type B
- type C: Haws type
- type D
- type E: (brachymetacarpia and brachymetatarsia)
- types B and E combined: Ballard syndrome or Pitt-Williams type
Brachydactyly can be either occur in isolation or be associated with syndromic as well as non-syndromic conditions:
- non syndromic
The differential for other causes of short digits include:
- 1. Den hollander NS, Hoogeboom AJ, Niermeijer MF et-al. Prenatal diagnosis of type A1 brachydactyly. Ultrasound Obstet Gynecol. 2001;17 (6): 529-30. doi:10.1046/j.1469-0705.2001.00428.x - Pubmed citation
- 2. Nguyen ML, Jones NF. Undergrowth: brachydactyly. Hand Clin. 2009;25 (2): 247-55. doi:10.1016/j.hcl.2009.02.003 - Pubmed citation
- 3. . Human Malformations and Related Anomalies. Oxford University Press. (2005) ISBN:019974808X. Read it at Google Books - Find it at Amazon
- 4. Castriota-Scanderbeg A, Dallapiccola B. Abnormal Skeletal Phenotypes. Springer. (2006) ISBN:3540303618. Read it at Google Books - Find it at Amazon
- 5. Temtamy SA, McKusick VA. The genetics of hand malformations. Birth Defects Orig. Artic. Ser. 1979;14 (3): i-xviii, 1-619. Pubmed citation