Zhang Yingying, Xiong Weixi, Lu Lu, Zhou Dong
Department of Neurology, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China.
Department of Neurology, West China Hospital of Sichuan University, Chengdu 610041, Sichuan, China.
Brain Res. 2020 Jun 15;1737:146796. doi: 10.1016/j.brainres.2020.146796. Epub 2020 Mar 17.
Recently, expanded intronic TTTCA and TTTTA repeat in SAMD12 were identified in families with familial cortical myoclonic tremor with epilepsy (FCMTE). We conducted to this study to clarify the genetic etiology and to describe the clinical, neurophysiologic, and imaging features in two unrelated Chinese families with FCMTE. In this study, we performed the RP-PCR and long-range PCR analysis to examine and verifyTTTCA and TTTTA expansions in five affected members whose severities of cortical tremor, neuropsychology and MRI were also evaluated. Reliable clinical information was collected from another two affected members. Our results revealed that expansions of intronic TTTCA and TTTTA repeats in SAMD12 were both identified in all five affected subjects. All seven affected living patients had cortical tremor with a median age at onset of 16.4 years (range, 10-22 years). Convulsions occurred in 5 of 7 with a median age at onset of 32.4 years (range, 10-42 years). Among five patients evaluated for cortical tremor severity and psychiatric comorbidity, two patients had severe cortical tremor, anxiety and depression. Abnormal brain MRI findings including the possible existence of demyelination, severe atrophy of the cerebral hemisphere and abnormal bilateral symmetrical signals in the globus pallidus were observed in three patients, respectively. These results further expanded the known genotype in two Chinese families affected with FCMTE. Border clinical spectrum needs to be confirmed in future studies from additional FCMTE families genetically diagnosed.
最近，在患有家族性皮质肌阵挛性震颤伴癫痫（FCMTE）的家族中，发现SAMD12基因内含子中的TTTCA和TTTTA重复序列有所扩展。我们开展这项研究，以阐明两个无关的中国FCMTE家族的遗传病因，并描述其临床、神经生理学和影像学特征。在本研究中，我们对5名受影响成员进行了RP-PCR和长程PCR分析，以检测和验证TTTCA和TTTTA的扩展情况，同时还评估了他们的皮质震颤严重程度、神经心理学状况和MRI表现。从另外两名受影响成员那里收集了可靠的临床信息。我们的结果显示，在所有5名受影响的受试者中均发现了SAMD12基因内含子中TTTCA和TTTTA重复序列的扩展。所有7名在世的受影响患者均有皮质震颤，发病年龄中位数为16.4岁（范围为10 - 22岁）。7名患者中有5名发生惊厥，发病年龄中位数为32.4岁（范围为10 - 42岁）。在评估皮质震颤严重程度和精神共病的5名患者中，有两名患者有严重的皮质震颤、焦虑和抑郁。分别在3名患者中观察到异常的脑部MRI表现，包括可能存在的脱髓鞘、大脑半球严重萎缩以及苍白球双侧对称信号异常。这些结果进一步扩展了两个中国FCMTE家族中已知的基因型。未来需要对更多经基因诊断的FCMTE家族进行研究，以确认临床谱系边界。
