晚发型甲基丙二酸血症cblC型2例报告及文献复习  

Late-onset methylmalonic acidaemia CblC type:Two case reports and literature review

作　　者：孙萌[1] 周冉 张新颖[1] 程亚颖[1] SUN Meng;ZHOU Ran;ZHANG Xinying;CHENG Yaying(Department of Pediatrics,General Hospital,Hebei Province,Shijiazhuang 050051,China)

机构地区：[1]河北省人民医院儿科,河北石家庄050051

出　　处：《吉林大学学报（医学版）》2024年第5期1420-1425,共6页Journal of Jilin University：Medicine Edition

基　　金：河北省卫健委医学科学研究项目(20230358)。

摘　　要：目的:探讨2例晚发型甲基丙二酸血症(MMA) cblC型患儿的临床表型和基因型特征,为临床早期识别MMA提供依据。方法:收集2例晚发型MMA cblC型患儿的临床表型、生化检查结果、血尿有机酸分析、神经影像学检查、脑电图和基因型等临床资料,并结合相关文献复习,分析该病的特征。结果:2例患儿均为女性,青少年期起病。患儿1以精神症状起病,患儿2以认知障碍起病,2例患儿均出现双下肢无力和语言障碍。初诊时血清同型半胱氨酸(Hcy)水平均重度升高,尿甲基丙二酸水平升高,头颅磁共振显像均提示脑萎缩,脑电图均提示双侧大脑半球慢波活动增多,患儿2双侧额区和颞区癫痫样放电,基因检测显示MMACHC基因c. 482G>A突变。2例患儿均给予维生素B12肌肉注射,同时口服叶酸、维生素B6、左卡尼汀和甜菜碱。2例患儿症状均改善,血清Hcy水平降低,尿甲基丙二酸水平恢复正常。结论:晚发型MMA cblC型表型多样,以神经精神损害为主,基因型以c. 482G>A突变最为常见。血清Hcy水平升高和脑萎缩可作为晚发型cblC型患儿早期识别的生物标志物。Objective:To discuss the clinical phenotype and genotype characteristics of two pediatric patients with late-onset methylmalonic acidemia(MMA)cblC type,and to provide the basis for early clinical recognition of MMA.Methods:The clinical data of two pediatric patients with late-onset MMA cblC type were collected,including clinical phenotypes,biochemical detection results,blood and urine organic acid analyses,neuroimaging,electroencephalograms,genotypes and so on.The characteristics of the disease were analyzed in combination with the related literature review.Results:Both pediatric patients were female,with onset in adolescence.Patient 1 presented with psychiatric symptoms,while pediatric patient 2 presented with cognitive impairment.Both pediatric patients experienced weakness in both lower limbs and speech disorders.At initial diagnosis,the serum homocysteine(Hcy)levels were severely increased,the urine methylmalonic acid levels were increased,the brain magnetic resonance imaging results indicated brain atrophy,and the electroencephalogram results showed the increased slow wave activity in both cerebral hemispheres.The pediatric patient 2 exhibited epileptiform discharges in bilateral frontal and temporal regions.The genetic testing results showed the c.482G>A mutation in the MMACHC gene.Both two pediatric patients were treated with intramuscular injections of vitamin B12,along with oral folic acid,vitamin B6,levocarnitine,and betaine.The symptoms of two patierts were improved,the serum Hcy levels were decreased,and the urine methylmalonic acid levels returned to normal.Conclusion:The phenotype of late-onset MMA cblC type is diverse,primarily involving neuropsychiatric impairment,with the c.482G>A mutation being the most common genotype.The increasing of serum Hcy levels and brain atrophy can serve as the biomarkers for the early recognition of late-onset cblC type pediatric patients.

关 键 词：甲基丙二酸血症 自身免疫性脑炎 同型半胱氨酸 脑萎缩 基因型 

分 类 号：R596[医药卫生—内科学]