The hand in Smith-Magenis syndrome (deletion 17p11.2): evaluation by metacarpophalangeal pattern profile analysis

Background: Brachydactyly has been described on physical examination in patients with Smith-Magenis syndrome (SMS). Metacarpophalangeal pattern profile analysis (MCPPPA), a method of graphic depiction of the relative size of the bones of the hand, has been used to objectively evaluate radiographs of the hand in patients with SMS in two small series: a single case and a study of four patients. This technique has confirmed brachydactyly and has suggested conflicting MCPPPA results. Objective: The purpose of our study was to evaluate the hand by MCPPPA in a large series of patients with SMS. Patients and methods: We measured the bones of the hand and performed MCPPPA in 29 confirmed cases of SMS. Results: Our results in 29 patients demonstrated a different MCPPPA in patients with SMS than previously reported. The analysis confirmed brachydactyly and the previously described trend of more pronounced shortening of the distal bones relative to the more proximal bones, but also demonstrated a previously undescribed pattern: relative enlargement of the proximal phalanx of the thumb and middle phalanx of the fifth finger. However, statistical analysis suggested that the pattern was not highly characteristic. Conclusion: MCPPPA of 29 patients with SMS demonstrates a pattern different than previously reported, but not highly characteristic.