Department of Diagnostic and Technology, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
Department of Paediatric Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy.
Eur J Paediatr Neurol. 2023 May;44:25-27. doi: 10.1016/j.ejpn.2023.03.001. Epub 2023 Mar 22.
DNA deletions involving 6q22.1 region result in developmental encephalopathy (DE), often associated with movement disorders and epilepsy. The phenotype is attributed to the loss of the NUS1 gene included in the deleted region. Here we report three patients with 6q22.1 deletions of variable length all showing developmental delay, and rhythmic cortical myoclonus. Two patients had generalized seizures beginning in infancy. Myoclonic jerks had polygraphic features consistent with a cortical origin, also supported by cortico-muscular coherence analysis displaying a significant peak around 20 Hz contralateral to activated segment. Deletions in 6q22.1 region, similarly to NUS1 loss-of-function mutations, give rise to DE and cortical myoclonus via a haploinsufficiency mechanism. A phenotype of progressive myoclonic epilepsy (PME) may also occur.
6q22.1 区域的 DNA 缺失导致发育性脑病（DE），常伴有运动障碍和癫痫。该表型归因于缺失区域内包含的 NUS1 基因的缺失。我们在此报告三例 6q22.1 缺失的患者，缺失长度不同，均表现为发育迟缓，节律性皮质肌阵挛。两名患者在婴儿期开始出现全身性癫痫发作。肌阵挛性抽搐具有与皮质起源一致的多导睡眠描记特征，皮质-肌肉相干性分析也支持这一特征，该分析显示在激活节段对侧有一个约 20Hz 的显著峰值。6q22.1 区域的缺失与 NUS1 功能丧失突变类似，通过杂合子功能不足机制导致 DE 和皮质肌阵挛。也可能出现进行性肌阵挛性癫痫（PME）的表型。
