Follow-up of patients with congenital hypothyroidism and phenylketonuria from neonatal screening

The purpose of this study is to report the follow-up result of 253 children with congenital hypothyroidism (CHT) and 10 children with phenylketonuria (PKU) detected by neonatal screening between 1991 and 1994. In the CHT there were 203 permanent primary and 50 transient cases. The mean age of beginning treatment was about one month old. Both T4 and TSH in CHT patients were apparently abnormal in the initial stage of treatment and began to be controlled into acceptable ranges after two months of treatment. Similarly, their heights and weights were comparable with the norm after two months of treatment although they were shorter and lighter in the initial stage. In the PKU there were 5 typical and 5 atypical (BH4) type cases. Both heights and weights in typical PKU patients were comparable with the norm but those in atypical type were shorter and lighter. The performance of both developmental milestones and intelligence quotients in typical PKU patients was also better than atypical type. Early diagnosis and treatment, i.e. as soon as possible after delivery, is essential in children with CHT and PKU not only for normal mental development but also for normal growth.