Cornejo Verónica E, Cabello Juan Francisco A, Colombo Marta C, Raimann Erna B
Laboratorio de Enfermedades Metabólicas, Instituto de Nutrición y Tecnología de los Alimentos (INTA), Universidad de Chile, Santiago, Chile.
Rev Med Chil. 2007 May;135(5):631-5. doi: 10.4067/s0034-98872007000500011. Epub 2007 Jul 9.
The glucose transporter type 1 deficiency syndrome (GLUT-1 SD) (OMIM 606777) is an inborn error of metabolism of brain glucose transport. The characteristic clinical manifestations are seizures, hypotonia, developmental delay, microcephaly and hypoglycorrhachia. We report a girl with normal weight and height at birth. At 6 weeks of age she started with convulsions reaching up to 20 myoclonic seizures a day. She was treated with valproate, phenobarbital and carbamazepine without response. Blood analysis including aminoacids and acylcarnitines were all normal. The brain MRI showed frontal atrophy with an increased subarachnoidal space and Electroencephalography was abnormal. Blood glucose was 84 mg/dl and spinal fluid glucose 26 mg/dl with a ratio of 0.31 (Normal Ratio >0.65+/-00.1). These results suggested the diagnosis of GLUT-1 SD, and was confirmed with erythrocyte glucose uptake of 44% (Normal range 80-100%). A molecular study found the mutation 969del, C971T in exon 6 of the gene Glut-1. Treatment with a ketogenic diet was started immediately and after 7 days with this diet seizures ceased. Anticonvulsants were progressively suspended. At present, the patient is 6 years old, she continues on a ketogenic diet and supplements with L-carnitine, lipoic acid, vitamins and minerals. Growth and development are normal with an intelligence quotient of 103. It is concluded that it is necessary to include GLUT-1 SD in the differential diagnosis of children with early seizures that are non responsive to pharmacological treatment.
1型葡萄糖转运体缺乏综合征(GLUT-1 SD)(在线人类孟德尔遗传数据库编号606777)是一种脑葡萄糖转运代谢的先天性缺陷。其特征性临床表现为癫痫发作、肌张力减退、发育迟缓、小头畸形和脑脊液低糖。我们报告一名出生时体重和身高正常的女孩。6周龄时她开始出现惊厥,每天多达20次肌阵挛发作。她接受了丙戊酸盐、苯巴比妥和卡马西平治疗,但无反应。包括氨基酸和酰基肉碱在内的血液分析均正常。脑部磁共振成像显示额叶萎缩,蛛网膜下腔增宽,脑电图异常。血糖为84mg/dl,脑脊液葡萄糖为26mg/dl,比值为0.31(正常比值>0.65±0.1)。这些结果提示诊断为GLUT-1 SD,红细胞葡萄糖摄取率为44%(正常范围80-100%)进一步证实了该诊断。分子研究发现葡萄糖转运体1(Glut-1)基因第6外显子存在969del、C971T突变。立即开始生酮饮食治疗,7天后惊厥停止。抗惊厥药物逐渐停用。目前,该患者6岁,继续采用生酮饮食,并补充左旋肉碱、硫辛酸、维生素和矿物质。生长发育正常,智商为103。结论是,对于早期癫痫发作且药物治疗无效的儿童,在鉴别诊断中必须考虑GLUT-1 SD。