Objective: To summarize the clinical characteristics of children with SLC35A2 gene variants related congenital disorders of glycosylation (SLC35A2-CDG), so as to improve the clinicians' understanding of this disease. Methods: Clinical data and gene detection results of 6 epilepsy children with SLC35A2 gene variants were treated in the Department of Pediatrics Peking University First Hospital from April 2019 to February 2020 were analyzed retrospectively. Results: Six children with SLC35A2 gene variants were identified, including 1 male and 5 females. The onset age of seizure was 5.5 (ranged from 2 to 20) months. All 6 cases had epileptic spasms, 2 cases had focal seizures, 2 cases had myoclonic seizures, 1 case had tonic seizures and 1 case had generalized tonic-clonic seizures. All patients with SLC35A2 gene variants were diagnosed as infantile spasm with developmental delay. Four cases had microcephaly, 4 cases had micro skeletal abnormalities, 3 cases had hypotonia and facial dysmorphism, 2 cases had inverted nipples. Visual abnormality, auditory anomaly, congenital cardiac disease and feeding difficulty were observed in one patient. The electroencephalography showed hypsarrhythmia in 6 patients. The brain magnetic resonance imaging (MRI) showed thinning of corpus callosum in 3 patients, delayed myelination in 2 patients and normal brain MRI in 3 patients. There were 2 cases of in-frame deletions, 1 case of missense variant, 1 case of splice site variant, 1 case of 2.14 kb deletion in Xp11.23 (only containing SLC35A2 gene) and 1 case of SLC35A2 gene mosaicism. All 6 cases had de novo variants. The last follow-up age ranged from 18 to 52 months. One patient was seizure free and 5 patients still had frequent seizures after treatment with antiepileptic drugs. Conclusions: SLC35A2 gene variants are mainly de novo variants. The characteristics of patients with SLC35A2-CDG are seizures and developmental delay, infantile spasms are most common diagnosis, micro skeletal anomaly, microcephaly, hypotonia, facial dysmorphism were accompanied features.
目的： 总结SLC35A2基因变异相关的先天性糖基化障碍Ⅱ型的临床特点，以提高临床医生对本病的认识。 方法： 回顾性收集2019年4月至2020年2月在北京大学第一医院儿科就诊的SLC35A2基因变异致先天性糖基化障碍Ⅱ型的6例癫痫患儿病例资料，对其临床表现和基因检测结果进行分析。 结果： 6例SLC35A2基因变异致先天性糖基化障碍Ⅱ型患儿中女5例、男1例;癫痫起病年龄为5.5月龄（2月龄~1岁8月龄）；癫痫发作类型多样，6例均有痉挛发作，局灶性发作2例，肌阵挛发作2例，强直发作1例，全面强直-阵挛发作1例；6例诊断为婴儿痉挛症伴发育落后，小头、微小骨骼畸形4例，肌张力低下及面容异常3例，乳头内陷2例，视觉异常、听觉诱发电位异常、先天性心脏病及喂养困难见于同1例，脑电图高峰失律6例。头颅磁共振成像异常3例，显示胼胝体薄3例，髓鞘发育落后2例，正常3例。SLC35A2基因框内缺失2例，错义变异1例，剪切位点变异1例，1例在Xp11.23位点缺失2.14 kb（仅含SLC35A2基因），嵌合变异1例；6例均为新发变异。末次随访年龄1岁6月龄~4岁4月龄，其中1例癫痫发作已缓解，5例发作未控制。 结论： SLC35A2基因以新生变异为主，该基因导致的先天性糖基化障碍Ⅱ型表型特点为癫痫发作和发育迟缓，以婴儿痉挛症最常见，多伴小头、微小骨骼畸形、肌张力低下及面容异常。.
Keywords: Congenital disorders of glycosylation; Genes, SLC35A2; Spasm, infantile.