Metacarpophalangeal pattern profile analysis in Rubinstein-Taybi syndrome.

Metacarpophalangeal pattern profile (MCPP) was determined in 49 radiographs of 40 patients with Rubinstein-Taybi syndrome. Two recognizable hand profiles were seen, depending on the configuration of the thumb and on age. Patients with a straight thumb showed a short first proximal phalanx, and short third medial phalanx. Patients with a radially deviated thumb had a short first proximal phalanx. Depending on age, a relatively large (infancy) or markedly short (older patients) first distal phalanx was found. The similarity between the patients was high. A third group of patients did not show a particular hand profile, but only small hand bones. The pattern variability indices were high in all groups of patients. MCPP analysis in Rubinstein-Taybi syndrome seems to be a powerful, but not pathognomonic, diagnostic tool.