Itonaga T, Higuchi S, Shimura K, et al. - In patients with congenital hypothyroidism (CH), researchers determined the cutoff value for the levothyroxine (LT4) dosage as a predictor of the LT4 requirement after puberty. They retrospectively analyzed the LT4 dosage and clinical information on 99 individuals with CH who were followed at the participating hospitals from the neonatal period to 15 years of age or older. Findings suggested that an LT4 dosage above 4.7 µg/kg/day and below 1.8 µg/kg/day at age 1 year can assist to forecast permanent CH and transient CH, respectively.