RESUMEN
<p><b>OBJECTIVE</b>To study the features of DUOX2 mutations and genotype-phenotype relationship in children with congenital hypothyroidism (CH), in order to provide evidence for gene diagnosis and gene treatment of CH.</p><p><b>METHODS</b>Blood samples were collected from 10 CH children with thyromegaly. Genomic DNA was extracted from peripheral blood leukocytes. All exons of DUOX2 gene were analyzed using PCR and direct sequencing.</p><p><b>RESULTS</b>G3632A mutation in the exon 28 of DUOX2 that may result in arginine to histidine substitution at codon 1211 was found in one patient. T2033C mutation in the exon 17 of DUOX2 that may result in histidine to arginine substitution at codon 678 was found in three patients. They were all heterozygous mutations.</p><p><b>CONCLUSIONS</b>Heterozygous mutations in DUOX2 may affect protein function and cause CH. The relationship between DUOX2 genotypes and clinical phenotypes is unclear and needs further studies.</p>