Radiological assessment of the hand and wrist in phenylketonuria and hyperphenylalaninaemia.

A radiograph of the left hand and wrist was taken in 141 children and young adults with phenylketonuria and hyperphenylalaninaemia. Ten (7.1%) had a bony abnormality and, of these, six (4.3%) showed evidence of reduced bone density. Only one patient had evidence of spiculation of the lower ulnar metaphysis previously described in phenylketonuria. Bone maturity was also assessed in 130 patients by the Tanner-Whitehouse (TW2) method. In 28 patients (21.5%) bone age was less than chronological age by 1 year or more. Bone age delay was greater in younger children on a more restricted diet with a lower intake of natural protein.