Thyroid axis dysfunction in patients with Prader‐Willi syndrome during the first 2 years of life

Abstract

P>Introduction Prader-Willi syndrome (PWS) is a genetic disorder caused by the loss of expression of paternally transcribed genes in a highly imprinted region of chromosome 15q11-13. The clinical phenotype has been well characterized, mostly related to hypothalamic dysfunction. Even though central hypothyroidism has been documented in 20-30% of patients with PWS, thyroid function during the first 2 years of life has not been clearly defined. Objective To evaluate hypothalamic-pituitary-thyroid function in infant PWS patients. Study design Eighteen patients with PWS, aged 0 center dot 16-2 years, were included in a prospective study. PWS diagnosis was based on clinical features and molecular analysis. Serum total (T) T4, free (F) T4, T3 and thyroid-stimulating hormone (TSH) were evaluated in the patients with PWS included in the study. Serum hormone values were compared to those of a large reference population of the same age. Results In 13 of 18 patients with PWS (72 center dot 2%), serum TT4 and/or FT4 levels were below the 2 center dot 5th percentile of the reference population, while in only one PWS patient serum T3 was below this cut-off. Conclusion The results of this study suggest that transient or definitive thyrotropin-releasing hormone (TRH)-TSH thyroid axis dysfunction may frequently be present in infant PWS patients. Paediatricians should be aware of this dysfunction in this critical period of thyroid hormone action on neurological development.