Research Of Pathogenic Genes In 149 Children With Cerebral Palsy In China

Objective: To detect the mutation status of KANK1,GAD1,AP4 complex gene?including AP4E1,AP4B1,AP4M1 and AP4S1?of children with congenital cerebral palsy?CP?,to investigate the relationship between genotype and clinical phenotype,and explore the cause of congenital CP and new methods for prevention and early diagnosis of CP.Method: Using stratified random sampling method,we chose 149 cases of 1-12 years old children with congenital CP in the Prevention and Treatment for Child with Cerebral Palsy in Heilongjiang Province,the First Affiliated Hospital of Henan University of Traditional Chinese Medicine,the First Affiliated Hospital of Medical University Of Anhui,Children's Hospital of Shenzhen,and Encephalopathy Hospital of Traditional Chinese Medicine of Xi'an.We comprehensively evaluated the children with CP and collected the clinical data.Extracting the peripheral venous blood of patients,their parents and/or compatriots,we detected the gene mutation of KANK1,GAD1 and AP4 complex?including AP4E1,AP4B1,AP4M1 and AP4S1?by next generation sequencing and Sanger sequencing.Results: The male to female ratio of 149 children with CP was 1.87: 1?97: 52?.All the children were born at term,without remarkable risk factors.The types of CP were spastic diplegia?48,32.21%?,mixed type?27,18.12%?,spastic quadriplegia?26,17.45%?,spastic hemiplegia?25,16.78%?,dyskinetic?20,13.42%?,and ataxia type?3,2.01%?respectively.Among these,spastic type was the most common?99,66.44%?.The top five comorbid diseases were mental retardation,speech impairment,head deformity,visual dysfunction and epilepsy.After next generation sequencing and Sanger sequencing,6 pathogenic mutations involved KANK1 and AP4S1 were found in 6 cases?4%?.All the children with CP with gene mutations were male and had no family history of CP.Among them,two spastic diplegia compatriots with mental retardation,microcephaly and language dysfunction,carrying the insertion mutation of the KANK1 gene?c.1274₁275ins AGCTGT,p.427₄28ins Ala Val?;one spastic hemiplegia children with mental retardation,eyes esotropia,language barriers,microcephaly,abnormal behavior and autism spectrum disorders,carrying KANK1 missense mutations?c.2167C>T,p.Arg723Cys?;one spastic hemiplegia children without complications,carrying KANK1 missense mutations?c.3482A>G,p.Asn1161Ser?;one spastic quadriplegia children with mental retardation,language retardation and microcephaly,carrying KANK1 gene missense mutation?c.2110G>A,p.Asp704Asn?;one spastic quadriplegia children with mental retardation,language disorder,microcephaly and epilepsy,carrying KANK1 deletion mutations?c.3103₃105del,p.1039del?and AP4S1 nonsense mutations?c.289C>T,p.Arg97Ter?.These mutations are derived from their fathers.AP4S1 gene was autosomal recessive inheritance,while KANK1 gene was not clear.In addition to the nonsense mutation of AP4S1 gene,other mutations were reported for the first time.The proportion of CP children with microcephaly carrying gene mutations?83%?was higher than those without?16%?,and there was statistical significance between them?P < 0.05?.Conclusion: First,KANK1 and AP4S1 gene mutations may be pathogenic factors in Chinese children with cerebral palsy.Second,KANK1 and AP4S1 gene mutation could lead to spastic cerebral palsy.Third,Children with cerebral palsy caused by KANK1 and AP4S1 gene mutations more likely combined with microcephaly than that without.Forth,all of KANK1 mutations in children with cerebral palsy were from their fathers.Last,the clinical phenotype KANK1 mutations were various.