Brachydactyly is a common feature of pseudohypoparathyroidism (PHP) type Ia. We studied the longitudinal growth of the short bones in the hand of a 15-yr-old girl with PHP type Ia who had been followed for congenital hypothyroidism. Radiographs of the hand of the patient, who had been X-rayed every year since 2 yr of age, were studied. She showed cone-shaped epiphyses of the hand at 2 yr of age before showing brachydactyly. At 4 yr of age, she showed brachydactyly and an advanced bone age, and some short bones were prematurely fused at 6 yr of age. The short bones without cone-shaped epiphyses were also short as a result of a disturbance of the longitudinal bone elongation. In conclusion, the brachydactyly of PHP type Ia is thus considered to be caused by both early epiphyseal fusion with cone-shaped epiphyses and a disturbance of the longitudinal bone elongation.
Keywords: PHP type Ia; brachydactyly; children; cone-shaped epiphyses; longitudinal study.