Children with Congenital Hypothyroidism, Diagnosed After 1 Month of Life

Hwang, Jin Soon; Kim, Se Young; Shim, Kye Shik; Shin, Choong Ho; Yang, Sei Won

Abstract

PURPOSE
Congenital hypothyroidism(CH) is not uncommon disorder, leading to retardation of mental development and growth, if not treated early. The aim of this study is to determine the factors influencing IQ of children with CH, diagnosed after 1 month of life.
METHODS
: Thirteen children with CH were included. They had intelligence test by KEDI-WISC(Korean Educational Development Institute-Wechsler Intelligence Scale for Children) and their medical records were reviewed. Their T4, TSH, height, age at diagnosis were investigated retrospectively. To evaluate the influence of T4, TSH, height, age at diagnosis on IQ, children were divided into three groups ; athyroid(n=8), sublingual(n=3), inborn errors of thyroid hormone synthesis(n=2) according to the result of thyroid scan.
Results
: In athyroid group, IQ closely correlated to VIQ and PIQ and had close relationship to T4 at diagnosis(.p=0.0086, r=0.8427), but no relation to TSH. There was no difference in height, T4 TSH, and IQ between athyroid and sublingual group.
CONCLUSION
: The results suggest that intellectual function in children with CH, diagnosed after 1 month of life depends on serum level of T4 at diagnosis. Further study is mandatory to elucidate the relationship between final IQ and factors, including thyroid function, age at diagnosis, adequacy of treatment, etc.