Introduction: Central hypothyroidism is due to a deficiency of TRH/TSH.
Patient and Methods, Results: A 9 year old boy (07 Aug. 20) was referred for proportionate short stature (-2.7 SD). He complained of fatigue and had mild peripheral edema. His baseline T4 was 2.9 ug/dL(ref. 4.50-12.50 ug/dL) and TSH 0.04 uIU/ml (0.400-4.00). The TRH test showed low TSH <0.004 Ulu/ML (ref. 0.400-4.00) and low T4 2.70 (ref. 4.50-12.50 ug/dL). Prolactin concentrations were within normal range. MRI of sella showed enlargement ("tumor") which was significantly decreased after one year of treatment with sodium L thyroxine. Tests of pituitary reserve of growth hormone yielded normal growth hormone concentrations. Ultrasound of the thyroid showed homogenous thyroid with moderately decreased.
Genetic Analysis: The most likely genes involved in central hypothyroidism were sequenced: TSHB, IGSF1 and TRHR and no gene alterations were found. PROP1 mutations were not tested as the child did not have combined pituitary hormone deficits. Mutations in TBL1X and IRS4 are going to be analyzed in the near future.
Conclusion: We present a child with central hypothyroidism who manifested an enlargement of the pituitary gland which was almost totally removed by sodium L thyroxine treatment after one year.
Keywords: Central hypothyroidism, genetics, pituitary enlargement.
19 - 21 Sep 2019
European Society for Paediatric Endocrinology