MOGS基因新发突变致先天性糖基化障碍Ⅱb型一例并文献复习

Congenital disorders of glycosylation-Ⅱb caused by MOGS gene mutation:case report and literature review

目的探讨先天性糖基化障碍(congenital disorder of glycosylation,CDG)Ⅱb型的临床特征及遗传学特点,为CDG-Ⅱb型患儿的早期诊断、治疗和预后提供依据。方法对南方医科大学附属深圳妇幼保健院新生儿科收治的1例CDG-Ⅱb型患儿资料进行回顾性分析。以"先天性糖基化障碍Ⅱb型"、"先天性糖基化缺陷Ⅱb型"、"甘露糖基-低聚糖葡萄糖苷酶(mannosyl-oligosaccharide glucosidase,MOGS)"和"congenital disorders of glycosylation typeⅡb"、"congenital defects of glycosylation typeⅡb、"MOGS"等为关键词,分别对中国知网、维普数据库、万方数据库、生物医学文献数据库(PubMed)、Web of Science数据库自建库至2019年8月收录的文献进行检索,总结CDG-Ⅱb型患儿的临床特征及遗传学特点。结果本例患儿女,因"肌张力低下2 d"入院,主要表现为异常面部特征、肌张力低下、低通气、呼吸暂停、需鼻饲喂养、肝大、外生殖器发育不全,全外显子高通量测序分析发现编码MOGS的基因存在2处复合杂合突变,c.1598delT(p.F533Sfs*40)来自母亲,c.1619G>C(p.R540P)来自父亲,均为未报道过的突变。文献检索共收集4篇文献,包括本例共7例CDG-Ⅱb型患儿,其中表现为面部畸形6例;生殖器发育不全、肌张力低下、神经发育迟缓、喂养困难及肝大各5例;听力异常、低通气或呼吸暂停、低丙种球蛋白血症各4例;惊厥、头颅磁共振异常各3例。基因检测均为复合杂合突变,3例存活,4例死亡。结论生后有异常面部特征、肌张力低下、惊厥、低通气、呼吸暂停、喂养困难、肝大、外生殖器发育不全、低丙种球蛋白血症等临床表现的患儿,应高度怀疑CDG-Ⅱb型,多数患儿多系统受累,预后不良。

Objective To study the clinical features and genetic characteristics of congenital disorder of glycosylation-Ⅱb(CDG-Ⅱb)for early diagnosis and treatment.Method The data of the patient with CDG-Ⅱb admitted to our hospital was analyzed.Using keywords including"congenital disorders of glycosylation typeⅡb","congenital defects of glycosylation typeⅡb","mannosyl-oligosaccharide glucosidase(MOGS)",databases including CNKI,VP database,Wanfang database,PubMed and the Web of Science database were searched from the establishment of the database until August 2019.The clinical and genetic characteristics of CDG-Ⅱb were summarized.Result A 2-day-old female infant was admitted to hospital because of"hypotonia for 2 days".The clinical manifestations were abnormal facial features,hypotonia,hypoventilation,apnea,nasogastric feeding,hepatomegaly and external genital hypoplasia.Whole exome sequencing(WES)analysis showed two compound heterozygous mutations in the gene encoding MOGS,c.1598delT(p.F533Sfs*40)from mother and c.1619G>C(p.R540P)from father,all of which were unreported novel mutations.A total of 7 cases of CDG-Ⅱb patients including our patient were analyzed and reported in 4 articles.These 7 cases were characterized by facial deformity(6 cases),hypoplastic genitalia(5 cases),hypotonia(5 cases),neurodevelopmental delay(5 cases),feeding difficulties(5 cases),hepatomegaly(5 cases),abnormal hearing(4 cases),hypoventilation or apnea(4 cases),hypogammaglobulinemia(4 cases),convulsion(3 cases)and abnormal brain magnetic resonance imaging(3 cases).The mutations of MOGS gene in all 7 patients were compound heterozygous mutations.As for the prognosis,3 cases were alive and 4 cases were dead.Conclusion CDG-Ⅱb should be considered in children with abnormal facial features,hypotonia,convulsion,hypopnea,apnea,feeding difficulties,hepatomegaly,external genital hypoplasia,hypogammaglobulinemia and other clinical manifestations.Patients with CDG-Ⅱb may have multi-organ involvement and poor prognosis.