RESUMO
Objective To investigate the features and characteristics of GLIS3 gene mutation in patients with congenital hypothyroidism(CH),and to establish the theoretical basis for gene diagnosis and prenatal diagnosis of CH.Methods Genomic DNA was extracted from peripheral blood leukocytes of 50 patients with CH who were collected from February 2007 to November 2016 in Shandong Province.The exon 2 to 11 of GLIS3 were amplified with 11 pairs of sequence specific primers designed by Primer 5.0.Polymerase chain reaction and the first generation of sequencing method(Sanger sequencing) were used to detect the mutation.Comparison of the sequencing results with the GLIS3 reference sequence (National Center for Biotechnology Information Reference Sequence:NC_000009.12) helped to screen gene mutations.Results The 50 CH patients included 22 boys and 28 girls,and the sex ratio was 1.0 ∶ 1.3.The mean age was (2.5 ± 0.5) years.Six cases (12％) had thyroid gland hypoplasia,23 cases (46％) had thyroid gland agenesis and 21 cases(42％) with ectopic thyroid gland.C2507A missense mutation was found in exon 10 of GLIS3 in a thyroid gland agenesis case,which might result in proline to glutamine substitution at codon 836.One mutant (rs780019691,c.C289T) was detected which was nonsense mutation (Arg→Stop) in another thyroid gland agenesis child.Conclusions The mutation rate of GLIS3 gene is very low in CH children of Shandong province.Further studies are needed to investigate the relationship between GLIS3 genotypes and clinical phenotypes.