Wilson's disease presenting with rickets.

Abstract

Wilson's disease is an inherited disorder of copper metabolism. Resultant kidney damage can induce metabolic bone disease, and in children the radiographic manifestations are indistinguishable from those of classical rickets. The patient who is the subject of this review was originally diagnosed as having vitamin D-resistant rickets. He had been well until the age of eight years, when pain and weakness of both knees developed in association with fever. Radiographs of knees and wrists (Fig. 1) taken at another hospital disclosed rachitic changes. Anemia, hypophosphatemia, and hypocalciuria were found. A diagnosis of vitamin D-resistant rickets was made. Treatment with vitamin D at a dose of 100,000 units daily induced symptomatic and radiographic evidence of remission (Fig. 2), but vitamin D intoxication supervened and the drug was discontinued at age ten. Initial evaluation at The New York Hospital in 1966, when the patient was eleven years old, showed return of rachitic changes on radiographs of the wrists and knees, a normal intravenous pyelogram, a serum calcium of 10.1 mg per 100 cc, and serum phosphorus of 2.2 mg per 100 cc. Vitamin D therapy was resumed with a dose of 20,000 units daily. Repeat films showed osteochondritis dissecans at the knees, rachitic changes, and a healing fracture of the distal radius (Fig. 3). In January 1967 a slit-lamp examination of the cornea, requested to evaluate the possible presence of calcium deposition, instead disclosed Kayser-Fleischer rings. Serum copper and ceruloplasmin were found to be low. A detailed neurological examination revealed slight tremor of tongue, moderate hyperreflexia, and mild terminal tremor. The liver and spleen were both slightly enlarged. A liver biopsy showed no fibrosis, but hepatic cell nuclei were seen to be enlarged and filled with glycogen. This latter finding is characteristic of first stage Wilson's disease. Members of the patient's immediate family were found to have low serum ceruloplasmin and copper levels. A sister has hepatomegaly, Kayser-Fleischer rings, and abnormal liver function studies The patient, at the age of twelve years, is currently receiving penicillamine 125 mg four times daily with pyridoxine 25 mg daily. This review is intended to draw attention to the radiologic manifestations of copper-induced nephropathy suffered by patients with Wilson's disease during a period of growth, when rickets may develop. This syndrome should be considered in the differential diagnosis of rickets, especially in the older child. It is hoped that children with Wilson's disease, who might otherwise be considered to have Fanconi's syndrome or vitamin D-resistant rickets, may be recognized early in the course of their disease. Under present modes of medical management, using D-penicillamine and low-copper diet, these patients can be spared an inexorably fatal disease, hopefully before significant morbidity has occurred.