GYS2基因变异致糖原贮积症0型两姐弟及其表型差异

Glycogen storage syndrome type 0 caused by GYS2 gene variation and phenotypic differences between two siblings

目的明确1例反复低血糖惊厥发作伴语言发育迟缓患儿的遗传学病因,为家系遗传咨询和精准治疗提供依据。方法收集患儿的临床资料,提取患儿、姐姐及父母外周血样DNA,采用全外显子组二代测序进行遗传学分析并行Sanger测序验证。结果患儿反复夜间低血糖伴惊厥发作,姐姐仅存在空腹低血糖。全外显子检测结果显示患儿及姐姐均携带GYS2基因第5外显子c.731T>A(p.M244L)和第6外显子c.928G>A(p.G244S)复合杂合变异,既往未见报道,其母亲携带c.731T>A(p.M244L)变异,父亲携带c.928G>A(p.G244S)变异。结论GYS2基因c.731T>A(p.M244L)和c.928G>A(p.G244S)复合杂合变异为本例糖原贮积症0型患儿的遗传学病因,上述结果为该家系的遗传咨询提供了基础;患儿低血糖时惊厥发作易被误诊为癫痫,但对抗癫痫治疗无效,可通过改善饮食维持血糖稳定控制发作。

Objective To provide a basis for genetic counseling and clinical precision therapy by exploring the genetic etiology of a child with recurrent hypoglycemia convulsion accompanied by language retardation.Methods Peripheral blood samples were obtained from the proband,his sister and his parents.Whole genomic DNA was extracted and analyzed by the whole exon gene sequencing and confirmed by Sanger sequencing.Results The proband and his sister were found to carry compound heterozygous variants c.731T>A(p.M244L)and c.928G>A(p.G244S)of the GYS2 gene,which had not been reported in the past,the c.731T>A(p.M244L)site was derived from the maternal heterozygous mutation,while c.928G>A(p.G244S)site from the father heterozygous mutation.Conclusion The compound heterozygous variants c.731T>A(p.M244L)and c.928G>A(p.G244S)of the GYS2 gene were the genetic cause of glycogen storage syndrome type 0 in children,providing basis for family genetic counseling.When the patient had Hypoglycemia often accompanied with convulsions,which was easy to be misdiagnosed as seizures,and the antiepileptic treatment was ineffective.After genetic diagnosis,the seizure can be controlled by improving diet to maintain blood glucose stability.