Thyroid involvement in cystinosis]

Thyroid function was assessed in 15 children with cystinosis and it was abnormal in 12. Three of these children were clearly hypothyroid and in the other 9 there were abnormalities of TSH or in the response to TRF. Compensated hypothyroidism is frequent in cystinosis and may be one factor in the severe growth retardation in this condition. The preliminary results of replacement therapy support this hypothesis.