Lim Byung Chan, Hwang Hee, Kim Hunmin, Chae Jong-Hee, Choi Jieun, Kim Ki Joong, Hwang Yong Seung, Yum Mi-Sun, Ko Tae-Sung
Department of Pediatrics, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
Department of Pediatrics, Asan Medical Center Children's hospital, University of Ulsan College of Medicine, Seoul, Republic of Korea.
Epilepsy Res. 2015 Jan;109:34-9. doi: 10.1016/j.eplepsyres.2014.10.008. Epub 2014 Oct 28.
The deletion of a sodium channel gene cluster located on chromosome 2q24.3 is associated with variable epilepsy phenotypes, including Dravet syndrome and migrating partial seizures of infancy. Although SCN1A is considered as the major contributor to the epilepsy phenotype, the role of other sodium channel genes that map within this cluster has not been delineated. We presented five new cases with a chromosome 2q24.3 deletion involving SCN1A and investigated their epilepsy phenotype in relation to the extent of the deletion. Three cases with deletion of the whole sodium channel gene cluster (SCN3A, SCN2A, SCN1A, SCN9A, and SCN7A) exhibited a complex epilepsy phenotype that was atypical for Dravet syndrome and suggestive of migrating partial seizures of infancy: early seizure onset (before 2 months of age), severe developmental delay from seizure onset, multifocal interictal spikes, polymorphous focal seizures, and acquired microcephaly. Two cases with partial deletion of SCN1A and SCN9A and whole SCN1A deletion had an epilepsy phenotype of Dravet syndrome. A literature review of cases with chromosome 2q24.3 deletion revealed that, in most Dravet syndrome cases, it does not involve SCN2A and SCN3A, whereas a complex epilepsy phenotype that is shared with migrating partial seizures of infancy was associated with cases of deletion of the whole sodium channel gene cluster.
位于2q24.3染色体上的一个钠通道基因簇的缺失与多种癫痫表型相关，包括德雷维特综合征和婴儿期游走性部分性癫痫发作。尽管SCN1A被认为是癫痫表型的主要促成因素，但该基因簇内其他钠通道基因的作用尚未明确。我们报告了5例涉及SCN1A的2q24.3染色体缺失的新病例，并根据缺失范围研究了他们的癫痫表型。3例整个钠通道基因簇（SCN3A、SCN2A、SCN1A、SCN9A和SCN7A）缺失的病例表现出一种复杂的癫痫表型，这对于德雷维特综合征来说是非典型的，提示婴儿期游走性部分性癫痫发作：癫痫发作早发（2个月龄前）、癫痫发作起病后严重发育迟缓、多灶性发作间期棘波、多形性局灶性癫痫发作和后天性小头畸形。2例SCN1A和SCN9A部分缺失以及SCN1A完全缺失的病例具有德雷维特综合征的癫痫表型。对2q24.3染色体缺失病例的文献综述显示，在大多数德雷维特综合征病例中，该缺失不涉及SCN2A和SCN3A，而与婴儿期游走性部分性癫痫发作共有的复杂癫痫表型与整个钠通道基因簇缺失的病例相关。
