Small patella syndrome.

We report on 2 sporadic cases of small patella syndrome (coxo-podo-patellaire syndrome) most probably representing new mutations. Both children showed retarded patellar bone age (small patellae in Patient 1 and absent patellae in Patient 2) and pelvic abnormalities. Patient 1 who was fully investigated had an unusual facies with characteristic morphological abnormalities of the forefoot and generalized bone changes. Patient 2 was not available for examination and only X-ray films of his knees, pelvis, and chest were available. These were all abnormal. He was said to have an "unusual facies" with flattened nose and prominent forehead but no further information was available. We think that small patella syndrome (coxo-podo-patellaire syndrome) is a generalized bone dysplasia with morphological and diagnostic radiographic appearances.