糖原贮积症Ⅸ型患儿PHKA2基因新变异导致的剪切异常  

Splicing abnormalities caused by a novel mutation in the PHKA2 gene in children with glycogen storage disease type IX

作　　者：张志华 郑必霞[2] 卓玉杰 金玉[1] 刘志峰[1] 郑玉灿[1] Zhang Zhihua;Zheng Bixia;Zhuo Yujie;Jin Yu;Liu Zhifeng;Zheng Yucan(Department of Gastroenterology,Children’s Hospital of Nanjing Medical University,Nanjing 210008,China;Nanjing Key Laboratory of Pediatrics,Children’s Hospital of Nanjing Medical University,Nanjing 210008,China)

机构地区：[1]南京医科大学附属儿童医院消化科,南京210008 [2]南京医科大学附属儿童医院儿科学重点实验室,南京210008

出　　处：《中华肝脏病杂志》2023年第4期428-432,共5页Chinese Journal of Hepatology

基　　金：国家自然科学基金(81570470);江苏省妇幼保健协会科研课题(FYX202101)。

摘　　要：目的糖原贮积症Ⅸ型(GSD-Ⅸ)是一种罕见的磷酸肌酸化激酶缺乏导致的原发性糖代谢异常,由一系列基因致病性变异引起。现对1例肝大患儿进行临床特征总结、基因分析、变异功能验证,明确其致病原因。方法收集1例GSD-Ⅸ患儿的临床资料,采集患儿及其父母外周血提取基因组DNA,应用二代测序对患者进行基因诊断,对疑似变异进行Sanger测序验证并行生物信息学分析,应用RT-PCR和一代测序对可疑剪接变异进行体内功能验证。结果患儿表现为肝大、转氨酶和甘油三酯增高,肝穿刺病理检查结果提示糖原贮积症。基因测序发现患儿PHKA2基因存在c.285+2_285+5delTAGG半合子变异。Sanger测序验证提示患儿母亲为该变异杂合型,患儿父亲为野生型。HSF3.1及ESEfinder等软件预测该基因变异会影响剪接。患儿及其母亲外周血RT-PCR证实该变异会引起PHKA2基因组成型剪接时外显子3的跳跃。结论PHKA2基因半合子变异(c.285+2_285+5delTAGG)为患者的致病原因,新变异位点的检出丰富了PHKA2基因的变异谱,为该家系的遗传咨询提供了依据。Objective Glycogen storage disease type IX(GSD-IX)is a rare primary glucose metabolism abnormality caused by phosphorylase kinase deficiency and a series of pathogenic gene mutations.The clinical characteristics,gene analysis,and functional verification of a mutation in a child with hepatomegaly are summarized here to clarify the pathogenic cause of the disease.Methods The clinical data of a child with GSD-IX was collected.Peripheral blood from the child and his parents was collected for genomic DNA extraction.The patient’s gene diagnosis was performed by second-generation sequencing.The suspected mutations were verified by Sanger sequencing and bioinformatics analysis.The suspected splicing mutations were verified in vivo by RT-PCR and first-generation sequencing.Results Hepatomegaly,transaminitis,and hypertriglyceridemia were present in children.Liver biopsy pathological examination results indicated glycogen storage disease.Gene sequencing revealed that the child had a c.285+2_285+5delTAGG hemizygous mutation in the PHKA2 gene.Sanger sequencing verification showed that the mother of the child was heterozygous and the father of the child was of the wild type.Software such as HSF3.1 and ESEfinder predicted that the gene mutation affected splicing.RT-PCR of peripheral blood from children and his mother confirmed that the mutation had caused the skipping of exon 3 during the constitutive splicing of the PHKA2 gene.Conclusion The hemizygous mutation in the PHKA2 gene(c.285+2_285+5delTAGG)is the pathogenic cause of the patient’s disease.The detection of the novel mutation site enriches the mutation spectrum of the PHKA2 gene and serves as a basis for the family’s genetic counseling.

关 键 词：糖原贮积症Ⅸ型 PHKA2基因 二代测序 剪接异常 

分 类 号：R725.8[医药卫生—儿科]