Department of Medical Genetics, Bezmialem Vakıf University School of Medicine, İstanbul, Turkey
Department of Radiology, Bezmialem Vakıf University School of Medicine, İstanbul, Turkey
Balkan Med J. 2018 Jul 24;35(4):336-339. doi: 10.4274/balkanmedj.2017.0986. Epub 2018 Mar 16.
The gene encodes the α-subunit of the large conductance, voltage, and calcium-sensitive potassium channel (BK channels) that plays a critical role in neuronal excitability. Heterozygous mutations in were first illustrated in a large family with generalized epilepsy and paroxysmal nonkinesigenic dyskinesia. Recent research has established homozygous mutations accountable for the phenotype of cerebellar atrophy, developmental delay, and seizures.
Here, we report the case of a patient with a novel homozygous truncating mutation in KCNMA1 (p.Arg458Ter) presenting with both the loss- and gain-of-function phenotype with paroxysmal dyskinesia, epilepsy, intellectual delay, and corticospinal–cerebellar tract atrophy.
This report extends the mutation phenotype with a patient who carries a novel frameshift variant, presenting with both the gain- and loss-of-function phenotypes along with spinal tract involvement as a novel characteristic.
该基因编码大电导、电压和钙敏感钾通道（BK 通道）的 α 亚基，在神经元兴奋性中起着关键作用。在一个具有全身性癫痫和阵发性非运动性运动障碍的大家族中首次描述了 基因的杂合突变。最近的研究已经确定纯合 基因突变是小脑萎缩、发育迟缓和癫痫的表型原因。
在这里，我们报告了一例 KCNMA1 中存在新型纯合截断突变（p.Arg458Ter）的患者，其表现为具有阵发性运动障碍、癫痫、智力迟钝和皮质脊髓-小脑束萎缩的功能获得和功能丧失表型。
本报告扩展了 基因突变表型，患者携带一种新型的移码变体，表现为功能获得和功能丧失表型，以及脊髓束受累，这是一种新的特征。
