6533b822fe1ef96bd127dceb

RESEARCH PRODUCT

Resistance to thyroid hormones. Study of an affected kindred diagnosed at neonatal age

subject

description

Resistance to thyroid hormones (RTH) is a rare condition of reduced activity of thyroid hormones on peripheral tissues and/or reduced suppression of TSH secretion by thyroid hormones. The disease is characterised by high serum levels of T3, T4, fT3 and fT4, and by unexpectedly normal or high TSH levels. The origin of the resistance has been recognised in a thyroid hormone receptor deficit, whose gene (TRβ) has been mapped on chromosome 3p24.3 and several mutations have been identified. The clinical presentation may vary among a large spectrum from hypo-, to eu-, to hyperthyroidism in different patients, even in the same family. The diagnosis of RTH at birth and in the first months of life is unfrequently suspected, because the disease doesn't appear or presents with mild simptoms. We report on the early diagnosis and therapy at neonatal age for a kindred (one male and two females) who have come to our attention because the first son was positive at neonatal screening for hypothyroidism. The recognition of the correct diagnosis in the propositus led to the study of the parents and subsequently to an early diagnosis for the following two sisters. It has been possible to identify and treat the only patient who presented simptoms of hypothyroidism; the others were clinically euthyroid and didn't need any treatment. The importance of the role of thyroid hormones in pediatric age, expecially in the first months of life, underlines the value of an early diagnosis in order to identify those patients who require treatment to garantee adeguate levels of thyroid hormones and then to prevent severe and permanent deficits of CNS and growth.