[PCDH19 gene mutations lead to epilepsy with mental retardation limited to females in 2 cases and literature review].

Epilepsy with mental retardation limited to females (EFMR) is a syndrome characterized by early onset heat-sensitive epilepsy of infancy or early childhood and generally limited to females, which previously reported that the cadherin gene superfamily subtype protocadherin 19 (PCDH19) gene is its pathogenic gene. We retrospectively analyzed the clinical data for 2 cases of EFMR patients with PCDH19 mutation diagnosed by Department of Pediatric Neurology of Xiangya Hospital, Central South University in 2015. Literature on PubMed, OMIM and HGMD relevant to this syndrome was reviewed, and the clinical characteristics were summarized accordingly. The 2 cases are consistent with the typical clinical manifestations of EFMR caused by PCDH19 mutations. Their seizures are heat sensitive, with or without screaming, and expressed in various forms. Cognitive impairment or autism-like performance were often identified in these patients, hematuria metabolic diseases screening was normal, no abnormal MRI imaging of the head, and de novo PCDH19 gene mutations were found in their epilepsy gene chip sequencing. It is noteworthy that this disease is very similar to the clinical manifestations of the Dravet syndrome due to the mutations of the neurotype sodium channel α1 subunit SCN1A. Therefore, in female patients whose clinical manifestations resemble to Dravet syndrome but SCN1A gene test were negative, EFMR with PCDH19 mutation should be taken into consideration. Early PCDH19 gene testingis of great significance because it not only helps clinicians to understand and analyze the prognosis of this disease, but also offers genetic counseling to the parents.限于女性的癫痫伴智力低下(epilepsy with mental retardation limited to females，EFMR)是一种其主要特点为婴儿期或幼儿早期发病、一般仅累及女性、发作有热敏感性的儿童期癫痫综合征，国外文献报道钙黏蛋白基因超家族亚型钙黏蛋白编码基因19(protocadherin 19，PCDH19)为其致病基因。作者对2015年中南大学湘雅医院小儿神经内科诊断的2例PCDH19新发突变所致的EFMR患者临床资料进行回顾性分析，并查阅PubMed，OMIM和HGMD等数据库，结合相关文献总结其临床特征。2例患儿均符合PCDH19突变致EFMR的典型临床表现，癫痫发作均存在热敏感性，发作时伴或不伴尖叫、发作形式多样、常伴有认知损害或自闭症样表现，血尿筛查未见明显异常，头颅磁共振成像无特征性改变，癫痫基因芯片测序分析发现PCDH19 新发突变。此疾病与神经型钠离子通道α1亚单位SCN1A突变所致的Dravet综合征临床表现极为相似，因此，对于SCN1A基因突变阴性的临床表现与Dravet综合征相似的患儿，特别是女性，应考虑PCDH19所致EFMR的可能。早期进行PCDH19基因检测，不仅对于临床医师了解和分析该病预后，而且对于向家长提供遗传咨询，都具有重要意义。.