Evaluation of the tshr gene reveals polymorphisms associated with typical symptoms in primary congenital hypothyroidism.

Primary congenital hypothyroidism (PCH) has an incidence of approximately 1 in each 3000-4000 live births. In the last two decades, nearly 50 types of the distinct inactivating mutations have already been described in the coding region of the tshr gene. The aim of present study was to investigate tshr gene mutations in patients with primary congenital hypothyroidism, analyzing a sample of 106 patients that were diagnosed with PCH. Genomic DNA was isolated from peripheral blood samples, and 10 exons from the TSH receptor were automatically sequenced. Five nucleotide alterations (P52T, N187N, A459A, L645L, and D727E. N187N and D727E polymorphisms) were associated with positive medical history. In view of the clinical, biochemical and molecular heterogeneity of the etiology of the PCH, the study of polymorphisms is critical for investigating the possible associations with prevailing symptoms of this disorder.