[Hypochondroplasia: importance of radiological findings in the differential diagnosis of short statures of different origin].

Hypochondroplasia is a genetic skeletal dysplasia characterized by disproportionate short stature, stocky appearance and several clinical and radiological features very similar, but much milder, than those of classical achondroplasia, including shortened and stubby long bones, decreased lumbo-sacral interpediculate distances, posterior scalloping of the lumbar vertebrae, metaphyseal flaring, and moderate macrocephaly. The condition may occasionally mimic short stature of familial, endocrine or metabolic origin. In the absence of clinical and laboratory diagnostic clues, radiological findings are of the utmost value in the diagnosis of this skeletal dysplasia and also in the differential diagnosis with other short-limbed dwarfisms. The genetic, clinical and radiological aspects of hypochondroplasia are briefly recalled, and the importance of some minor and frequently overlooked findings is stressed.