一例HEPACAM基因变异致伴皮层下囊肿的巨脑性脑白质病2B型患儿的分析  

Analysis of a child with megalencephalic leukoencephalopathy with subcortical cyst type 2B caused by HEPACAM variant

作　　者：徐敏 金波[1] 郭虎[1] Xu Min;Jin Bo;Guo Hu(Department of Neurology,Children’s Hospital of Nanjing Medical University,Nanjing,Jiangsu 210008,China)

机构地区：[1]南京医科大学附属儿童医院神经内科,210008

出　　处：《中华医学遗传学杂志》2020年第5期543-546,共4页Chinese Journal of Medical Genetics

摘　　要：目的探讨1例伴皮层下囊肿的巨脑性脑白质病(megalencephalic leukoencephalopathy with subcortical cyst,MLC)2B型患儿及其家系的临床特征与HEPACAM基因的变异情况。方法回顾分析1例HEPACAM基因变异导致的MLC2B型患儿的临床、影像资料及患儿母亲、舅舅的生长发育情况并复习相关文献。结果患儿,女,1岁7个月,因抽搐就诊,智力运动发育落后,头围异常增大,头颅磁共振成像提示两侧大脑半球脑白质呈广泛性长T1长T2信号、右前颞囊肿、脑回增宽、脑沟浅平。基因测序提示HEPACAM基因第3外显子存在c.437C>T错义变异,其母携带相同变异,父亲未发现异常。母亲及舅舅幼时有头围增大史,成年后母亲头围正常、舅舅头围仍大于正常成年人。结论该患儿携带HEPACAM基因一个杂合变异,诊断为MLC2B型。上述变异来源于母亲,MLC2B可能存在外显不全。Objective To explore the clinical features and genetic variant in a child featuring megalencephalic leukoencephalopathy with subcortical cyst(MLC)type 2B.Methods Clinical and imaging data of the child was collected.Potential variant of hepatocyte adhesion molecule(HEPACAM)gene was detected by Sanger sequencing.The growth and development of her mother and uncle was also reviewed.Results The patient,a 1-year-and-7-month female,presented with convulsion,mental retardation and abnormally increased head circumference.Cranial MRI revealed extensive long T1 long T2 signals in the white matter of bilateral cerebral hemisphere,right anterior sac cyst,cerebral gyrus widening,and shallow sulcus.Sanger sequencing identified a c.437C>T missense variant in exon 3 of the HEPACAM gene.The same variant was detected in her mother but not father.Her mother and maternal uncle both had a history of increased head circumference when they were young.In their adulthood,the head circumference was in the normal range but still greater than the average.Conclusion The heterozygous variant of the HEPACAM gene probably underlies the MLC2B in this child.The variant has derived from her asymptomatic mother,which suggested incomplete penetrance of the MLC2B.

关 键 词：巨颅 囊肿 脑白质病 HEPACAM基因 

分 类 号：R742[医药卫生—神经病学与精神病学]