Contribution of genetic factors to neonatal transient hypothyroidism

Background: The causes of neonatal transient hypothyroidism (NTH) remain incompletely understood. Whether it is influenced by genetic background is rarely discussed and remains unproven. A defect in thyroid peroxidase is a common cause of dyshormonogenesis of the thyroid gland in Taiwanese, with a novel mutation (2268insT) present in nearly 90% of alleles studied. Objective: To determine if the presence of this common mutation is associated with NTH in Taiwan. Methods: A mismatched primer was designed and used for this specific 2268insT mutation to screen 1000 normal babies and 260 babies with confirmed NTH. Results: The carrier rate for 2268insT in normal babies (1/200) was significantly lower than in babies with NTH (1/13; p