Study On GRIN3B Gene Mutation In Children With Tourette Syndrome

Objective Tourette syndrome is a neuropsychiatric disorder characterized by multiple motor tics and one or more vocal tics.The glutamate receptor gene families associated with this disease have become a hot topic in recent years,and many studies showed that a variety of gene of glutamate receptors were involved in the pathogenesis of Tourette syndrome.On the other hand,the GRIN3 B gene is one of the major members of the glutamate receptor gene family.The aim is to explore the association the gene with Tourette syndrome in children by screening mutations in the coding region of this gene.Methods All exon regions of GRIN3 B gene were sequenced by Illumina sequencing method,then preliminary screening mutation types of GRIN3 B gene of patients with TS according to sequencing analysis and bioinformatics,to verify the result by sangering sequencing finally.There were 51 TS children and 60 healthy controls in study.TS group include 51 children aged from 6 to 16 years old in the Affiliated Hospital of Qiingdao University from October 2015 to November 2016,mean age 9.78±3.64 years,consisting of 41boys?80.4%?,10 girls?19.6%?,and the criteria for admission are:?1?there are a variety of movement and one or more vocal movements within a certain period,although not necessarily at the same time;?2?the frequency of the movement can be strong and weak,but for more than one year;?3?before 18 years of age;?4?This obstacle can not be attributed to the physiological effects of some substance or other physical diseases;The healthy groups include 49 males?81.7%?and 11 females?18.3%?,with average age was29.08±2.89 years old.Selection criteria:?1?no nervous system and mental illness and other major physical diseases;?2?no neuropathy or psychosis in family;?3?volunteers who volunteered to participate in the clinical trial and sign informed consent.Then extracting DNA from 51 patients with TS and 60 controls,PCR was applied to amplify the encoding region of GRIN3 B gene and Sanger sequencing was used to sequence,then the sequencing results of GRIN3 B were compared with the NCBI gene encoding region sequence?NM₁38690.2?and controls to test whether these patients carried gene mutation.Results In this study,Sanger sequencing was used to sequence the GRIN3 B gene of TS group and control group,and we found two non synonymous mutation sites p.P154 S and p.L396 S in the TS group.The variation of rs113181909?c.C460T?results in thetranslating of proline to serine?p.P154S?,which is located in the highly conserved amino acid sequence.The variation of rs12978900?c.T1187C?led to the change of leucine to serine?p.L396S?,but it located in the non conservative sequence.There were no variation of rs113181909 and rs12978900 in the control group.The proline encoded changed into serine?p.P154S?and the leucine changed to serine?p.L396S?by bioinformatics analysis.Multiple sequence alignment of GRIN3 B were compared in human,cattle,mice,sheep,rat,and wild boar by DNAMAN software,we found that p.P154 S located in the highly conserved amino acid sequence and p.L396 S located in the non conservative sequence.Conclusion c.C460T?p.P154S?gene variant of GRIN3 B was found in 2 patients;c.T1187C?p.L396S?variant of GRIN3 B gene was found in 10 patients.The two peak sequencing maps were obtained by Sanger sequencing.Two abnormal GRIN3 B sites lead to change of protein,but the mechanism of GRIN3 B gene mutation leading to Tourette syndrome is not clear.