National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Brachydactyly type A2


Other Names:
BDA2; Mohr-Wriedt type brachydactyly; Brachymesophalangy 2
Categories:
This disease is grouped under:
Brachydactyly type A2 is a very rare condition affecting the middle bone (middle phalanx) of the index finger and the second toe. Typically, people affected by brachydactyly type A2 have very short (hypoplastic) middle bones of these digits. In some individuals, the bone above the middle phalanx (distal phalanx) is shifted as well, so that the fingers and toes may look misshapen. There have not been reports of other symptoms associated with brachydactyly type A2. Typically, brachydactyly type A2 does not require surgery, and affected individuals are able to use their hands normally.[1][2]
Last updated: 10/31/2016

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Showing of 18 |
Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Type A2 brachydactyly
Short index fingers and second toes
0009372
30%-79% of people have these symptoms
Clinodactyly of the 5th finger
Permanent curving of the pinkie finger
0004209
Short foot
Short feet
Small feet
[ more ] 		0001773
5%-29% of people have these symptoms
Aplasia/Hypoplasia of the middle phalanx of the 2nd finger
Absent/small middle index finger bone
Absent/underdeveloped middle index finger bone
[ more ] 		0009568
Short 2nd metacarpal
Shortened 2nd long bone of hand
0010038
Short middle phalanx of the 5th finger
Short middle bone of the little finger
Short middle bone of the pinkie finger
Short middle bone of the pinky finger
[ more ] 		0004220
Percent of people who have these symptoms is not available through HPO
2-3 toe syndactyly
Webbed 2nd and 3rd toes
0004691
Aplasia/Hypoplasia of the middle phalanx of the 5th finger
Absent/small middle bone of pinky finger
Absent/underdeveloped middle bone of little finger
Absent/underdeveloped middle bone of pinkie finger
Absent/underdeveloped middle bone of pinky finger
[ more ] 		0009161
Autosomal dominant inheritance 0000006
Broad hallux
Broad big toe
Wide big toe
[ more ] 		0010055
Hallux valgus
Bunion
0001822
Medially deviated second toe 0008096
Radial deviation of the 2nd finger 0009467
Short 2nd finger
Short index finger
Short index fingers
[ more ] 		0009536
Short hallux
Short big toe
0010109
Triangular shaped middle phalanx of the 2nd finger
Triangular shaped middle bone of index finger
0009575
Triangular shaped middle phalanx of the 5th finger
Triangular shaped middle little finger bone
Triangular shaped middle pinkie finger bone
Triangular shaped middle pinky finger bone
[ more ] 		0009182
Ulnar deviation of the 2nd finger 0009464
Showing of 18 |
Last updated: 7/1/2020
Brachydactyly type A2 is a genetic condition, meaning that it is caused by a change (mutation) in a person’s genes. Specifically, brachydactyly type A2 is caused by a mutation in one of two genes: BMPR1B or GDF5.[1] Mutations in areas of the genetic code that control a gene called BMP2 can also cause brachydactyly type A2.[2]

In families with multiple cases of brachydactyly type A2, it seems that the condition is inherited in an autosomal dominant manner.[1] This means that every child of a person affected by the condition has a 50% chance of having the condition themselves. 
Last updated: 10/31/2016
Brachydactyly type A2 is typically diagnosed by physical examination. A clinician may look at the hands and feet and determine that they seem to match what is commonly seen in brachydactyly type A2. X-ray may be used to get a better view of the bones in the fingers and toes. Genetic testing is typically not completed to confirm the diagnosis unless one is participating in a clinical trial.[3] 
Last updated: 10/31/2016

Testing Resources

  • The Genetic Testing Registry (GTR) provides information about the genetic tests for this condition. The intended audience for the GTR is health care providers and researchers. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The University of California San Francisco Limb Study is researching the genetic causes of limb malformations. They are looking for participants who only have problems with their limbs, such as fused or webbed fingers/toes, more than 5 fingers/toes, less than 5 fingers/toes, split hand and foot also called ectrodactyly, short fingers/toes, bent pinky fingers, extra long fingers, flexed fingers, club foot, etc. Visit the study’s website to learn more about who is eligible to take part in this study.

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) is a catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Brachydactyly type A2. Click on the link to view a sample search on this topic.

Selected Full-Text Journal Articles

  • The Orphanet Journal of Rare Diseases has published an article with information on this condition. This journal is affiliated with the Orphanet reference portal for information on rare diseases and orphan drugs.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. McKusick, VA, O'Neill, MJF, Hamosh, A, and Kniffin, CL. Brachydactyly, Type A2, ; BDA2. Online Mendelian Inheritance in Man (OMIM). March 20, 2013; http://www.omim.org/entry/112600.
  2. Liu, X, Gao, L, Zhao, A, Zhang, R, Ji, B, Wang, L, Zheng, Y, Zeng, B, Valenzuela, RK,He, L, and JMa. Identification of Duplication Downstream of BMP2 in a Chinese Family with Brachydactyly Type A2 (BDA2). PLoS One. April 7, 2014; 9(4):e94201. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3978006/.
  3. Temtamy SA and MS Aglan. Brachydactyly. Orphanet Journal of Rare Diseases. June 13, 2008; 3(15):https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2441618/.