Abstract
We shall describe the points in differentiating hypochondroplasia from achondroplasia. Recently we saw a female patient with hypochondroplasia which, according to Ravenna's report, is a different entity than achondroplasia. The patient was brought to us at the age of three years and seven months for evaluation of short stature and for genetic consultation. The following may be the important clinical points in differentiating hypochondroplasia from achondroplasia:
1 No facial and cranial deformity peculiar to achondroplasia such as nasal depression, frontal bossing or hydrocephalic skull
2 No trident deformity seen between the long and ring fingers
Then, roentgenographically, the following findings are not so remarkably expressed as those of achondroplasia in its own grade.
3 Protrusion of the greater and lesser trochanter
4 Champagne glass like deformity of the pelvic cavity
5 Ball-in-socket changes between the epiphysis and the metaphysis of the long and short tubular bones
6 Deep sciatic notches in anteroposterior view
