Shikun Ma1, Mingming Hu1, Hongbo Yang1, Xiaolan Lian1, Yanqiu Jiang1. 1. Departments of Medicine (S.M., Y.J.) and Endocrinology and Metabolism (M.H., H.Y., X.L.), Peking Union Medical College Hospital, 100730 Beijing, China.
Abstract
CONTEXT: A majority of patients with resistance to thyroid hormone (RTH) are asymptomatic, whereas some patients show signs of hyperthyroidism, or hypothyroidism, or both. Thyrotoxic periodic paralysis is the most common form of acquired periodic paralysis. However, it has not been reported in a patient with RTH up to now. OBJECTIVE: We evaluated a 36-year-old male patient from China with elevated serum free T4 and free T3 and inappropriately high TSH who presented with periodic paralysis. STUDY DESIGN: Clinical, biochemical, and radiological assessments, as well as DNA sequencing, were performed. RESULTS: The patient's laboratory tests revealed the following: TSH, 6.14 mIU/L (0.27-4.2 mIU/L); free T3, 12.85 pmol/L (2.8-7.1 pmol/L); free T4, 33.62 pmol/L (9.05-25.5 pmol/L); and serum SHBG, 19.4 nmol/L (18.3-54.1 nmol/L). No significant suppression of TSH was observed in the rapid TSH suppression test with somatostatin analogs. Compound muscle action potential after exercise of the patient was reduced by 58%. Sequencing of thyroid hormone receptor genes confirmed a C446S mutation in the THRβ gene. CONCLUSIONS: This is the first report of periodic paralysis as a new phenotype of RTH syndrome.
CONTEXT: A majority of patients with resistance to thyroid hormone (RTH) are asymptomatic, whereas some patients show signs of hyperthyroidism, or hypothyroidism, or both. Thyrotoxic periodic paralysis is the most common form of acquired periodic paralysis. However, it has not been reported in a patient with RTH up to now. OBJECTIVE: We evaluated a 36-year-old male patient from China with elevated serum free T4 and free T3 and inappropriately high TSH who presented with periodic paralysis. STUDY DESIGN: Clinical, biochemical, and radiological assessments, as well as DNA sequencing, were performed. RESULTS: The patient's laboratory tests revealed the following: TSH, 6.14 mIU/L (0.27-4.2 mIU/L); free T3, 12.85 pmol/L (2.8-7.1 pmol/L); free T4, 33.62 pmol/L (9.05-25.5 pmol/L); and serum SHBG, 19.4 nmol/L (18.3-54.1 nmol/L). No significant suppression of TSH was observed in the rapid TSH suppression test with somatostatin analogs. Compound muscle action potential after exercise of the patient was reduced by 58%. Sequencing of thyroid hormone receptor genes confirmed a C446S mutation in the THRβ gene. CONCLUSIONS: This is the first report of periodic paralysis as a new phenotype of RTH syndrome.
Authors: R E Weiss; B Chyna; P B Duell; Y Hayashi; T Sunthornthepvarakul; S Refetoff Journal: J Clin Endocrinol Metab Date: 1994-05 Impact factor: 5.958
Authors: Catherine S Mitchell; David B Savage; Sylvie Dufour; Nadia Schoenmakers; Peter Murgatroyd; Douglas Befroy; David Halsall; Samantha Northcott; Philippa Raymond-Barker; Suzanne Curran; Elana Henning; Julia Keogh; Penny Owen; John Lazarus; Douglas L Rothman; I Sadaf Farooqi; Gerald I Shulman; Krishna Chatterjee; Kitt Falk Petersen Journal: J Clin Invest Date: 2010-03-08 Impact factor: 14.808