Congenital hypothyroidism caused by new mutations in the thyroid oxidase 2 (THOX2) gene

Summary Objective  Congenital primary hypothyroidism (CH) occurs in one of 4000 births and in 20% of the cases CH is due to a defect in thyroid hormonogenesis. Candidate genes were examined to determine the precise aetiology of suspected dyshormonogenesis in CH. Design  The genes that code for thyroid peroxidase (TPO), pendrin (PDS), sodium iodide symporter (NIS) and thyroid oxidase 2 (THOX2) were sequenced directly from genomic DNA. Patients  Two girls found to have CH in the neonatal screening programme and suspected of having thyroid dyshormonogenesis were investigated to identify their molecular defect. Results  Patient A had a novel heterozygous 1 bp insertion in the THOX2 gene (ins602…