Trichorhinophalangeal syndrome type I in monozygotic twins discordant for hip pathology. Report on the morphological evolution of cone-shaped epiphyses and the unusual pattern of skeletal maturation.

A pair of monozygotic twin girls with trichorhinophalangeal syndrome type I (TRPS I), followed from 8.3 to 16.1 years of age, is described. Both showed typical dysmorphic features and severe short stature, but only one had Perthes-like changes in the right capital femoral epiphysis. The radiographic findings and evolutionary changes of phalangeal cone-shaped epiphyses (PCSE) of the hands are illustrated in this report. The unusual bone maturation and growth of the twins are also described. Both presented poor growth and delayed bone age until about 13 years, followed by marked acceleration of bone age and stunted pubertal height spurt.