The genetic testing of hereditary ataxias includes screening for CAG-repeat expansions as well as pathogenic variants and nontranslated oligonucleotide expansion, which can cause spinocerebellar ataxia (SCA). Genotype-phenotype correlations of several SCA subtypes are difficult to establish, and the underlying mechanisms remain unclear. Here, we report a 58-year-old male patient who presented with severe generalized ataxia, horizontal gaze-evoked nystagmus, cognitive impairment and a positive family history of gait difficulties. Genetic panel diagnostics revealed a new nonsense pathogenic variant in the CACNA1A gene (c.2983G>T; p. Glu995*) that segregated with the phenotype in three clinically affected family members. This gene is related to SCA type 6 (SCA6), episodic ataxia type 2, familial hemiplegic migraine type 1, among others. When it is supported by the clinical findings and family history, additional DNA sequencing beyond fragment length analysis should be performed.
Citations
Citations to this article as recorded by
The genotype–phenotype correlations of the CACNA1A-related neurodevelopmental disorders: a small case series and literature reviews Miriam Kessi, Baiyu Chen, Nan Pang, Lifen Yang, Jing Peng, Fang He, Fei Yin Frontiers in Molecular Neuroscience.2023;[Epub] CrossRef