Screening for Coding Variants in FTO and SH2B1 Genes in Chinese Patients with Obesity

OBJECTIVE To investigate potential functional variants in FTO and SH2B1 genes among Chinese children with obesity. METHODS Sanger sequencing of PCR products of all FTO and SH2B1 exons and their flanking regions were performed in 338 Chinese Han children with obesity and 221 age- and sex-matched lean controls. RESULTS A total of seven and five rare non-synonymous variants were identified in FTO and SH2B1, respectively. The overall frequencies of FTO and SH2B1 rare non-synonymous variants were similar in obese and lean children (2.37% and 0.90% vs. 1.81% and 1.36%, P>0.05). However, four out of the seven variants in FTO were novel and all were unique to obese children (p>0.05). None of the novel variants was consistently being predicted to be deleterious. Four out of five variants in SH2B1 were novel and one was unique to obese children (p>0.05). One variant (L293R) that was consistently being predicted as deleterious in SH2B1 gene was unique to lean control. While rare missense mutations were more frequently detected in girls from obesity as well as lean control than boys, the difference was not statistically significant. In addition, it's shown that the prevalence of rare missense mutations of FTO as well as SH2B1 was similar across different ethnic groups. CONCLUSION The rare missense mutations of FTO and SH2B1 did not confer risks of obesity in Chinese Han children in our cohort.