Normal Values for the fT3/fT4 Ratio: Centile Charts (0-29 Years) and Their Application for the Differential Diagnosis of Children with Developmental Delay.

ABSTRACT: Primary congenital hypothyroidism is easily diagnosed on the basis of elevated plasma levels of thyroid-stimulating hormone (TSH). In contrast, in the rare disorders of thyroid hormone resistance, TSH and, in mild cases, also thyroid hormone levels are within the normal range. Thyroid hormone resistance is caused by defects in hormone metabolism, transport, or receptor activation and can have the same serious consequences for child development as congenital hypothyroidism. A total of n = 23,522 data points from a large cohort of children and young adults were used to generate normal values and sex-specific percentiles for the ratio of free triiodothyronine (T3) to free thyroxine (T4), the fT3/fT4 ratio. The aim was to determine whether individuals with developmental delay and genetically c

SUBMITTER: Wilpert NM 

PROVIDER: S-EPMC11354987 | biostudies-literature | 2024 Aug

REPOSITORIES: biostudies-literature