triiodothyronine--reverse and Pseudohypoparathyroidism

This is a report about three children suffering from pseudo-hypoparathyroidism type I and moderate primary hypothyroidism. The thyroid dysfunction was characterised by slightly low plasma thyroxine and high basal TSH showing an increased response to TRH. T3 and rT3 were within normal limits, the size of the thyroid glands and also bone age were normal. The plasma concentrations of T4 and TSH and the response of TSH to TRH were no different during hypocalcemia from those obtained in normocalcemia during vitamin D treatment. Thyroxine treatment could normalize T4 and TSH. Moderate hypothyroidism is frequently present in pseudohypoparathyroidism. It has to be assumed that the same genetical defect of the second messenger, already proved to exist in the kidneys of patients with pseudohypoparathyroidism may also exist in the thyroid gland.

Topics: Adolescent; Calcium; Child; Female; Follicle Stimulating Hormone; Humans; Hypothyroidism; Luteinizing Hormone; Male; Pseudohypoparathyroidism; Thyrotropin; Thyroxine; Triiodothyronine; Triiodothyronine, Reverse