Analysis of thyroid stimulating hormone receptor gene mutation in children with hyperthyroidism

Abstract

Objective To explore the characterization of thyroid stimulating hormone receptor(TSHR) gene mutational spectrum in children with hyperthyroidism from Guangzhou. Methods Ninety children were diagnosed with hyperthyroidism from July 2009 to July 2014 in our institute. Their median age at diagnosis was(7.5±3.4) years, and there were 28 males and 62 females. Mutational analysis were performed by performing polymerase chain reaction(PCR) and DNA direct sequencing of exon 10 of TSHR gene. TSHR gene mutations from 50 unrelated healthy children were served as controls. The correlation between TSHR gene and hyperthyroidism in children was explored. Results A total of 3 mutations were identified in ninety children who were diagnosed with hyperthyroidism, one synonymous mutations(p.V614V), and two missense mutations(p.R707W and p. D727E). Mutation of p. V614V do not change amino acid and do not influence the structure and function of TSHR, no pathogenicity. p. R707W is a SNP associated with human cancers. The frequency of C allele of the D727E in children with hyperthyroidism was 86.7%, while 55.0% in the controls, significant different between the children with hyperthyroidism and the controls(P<0.01). In this study, a very high association between the D727E SNP and hyperthyroidism(OR=18.86, P<0.01) was found. Conclusion Three different mutations of TSHR gene exon 10 were identified in 90 children with hyperthyroidism, (c.1842A>G, p.V614V、c.2119C>T, p.R707W、c.2181G>C, p.D727E), there were association between p. D727E and hyperthyroidism, nor p. V614V and p. R707W. Finally, p. D727E may be correlated with hyperthyroidism in children. Key words: Hyperthyroidism; Children; Thyroid stimulating hormone receptor(TSHR); Gene; Mutation