ISSN : 2146-3123
E-ISSN : 2146-3131

Expanding the Phenotype of Homozygous KCNMA1 Mutations; Dyskinesia, Epilepsy, Intellectual Disability, Cerebellar and Corticospinal Tract Atrophy
Gözde Yeşil1, Ayşe Aralaşmak2, Enes Akyüz1, Dilara İçağasıoğlu3, Türkan Uygur Şahin4, Yavuz Bayram5
1Department of Medical Genetics, Bezmialem Vakıf University School of Medicine, İstanbul, Turkey
2Department of Radiology, Bezmialem Vakıf University School of Medicine, İstanbul, Turkey
3Department of Child Disease and Health, Bezmialem Vakıf University School of Medicine, İstanbul, Turkey
4Department of Child Neurology, Bezmialem Vakıf University School of Medicine, İstanbul, Turkey
5Mol. & Human Gene/Lupski Lab, Baylor College of Medicine, Texas, USA
DOI : 10.4274/balkanmedj.2017.0986
Pages : 336-339

Abstract

Background: The KCNMA1 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 KCNMA1 were first illustrated in a large family with generalized epilepsy and paroxysmal nonkinesigenic dyskinesia. Recent research has established homozygous KCNMA1 mutations accountable for the phenotype of cerebellar atrophy, developmental delay, and seizures.
Case Report: 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.
Conclusion: This report extends the KNCMA1 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.

Keywords : Cerebellar atrophy, dyskinesia, epilepsy, KCNMA1, spinal tract atrophy
Viewed : 4142
Downloaded : 249