Mantuano E, Veneziano L, Jodice C, Frontali M
Istituto di Neurobiologia e Medicina Molecolare del CNR, Roma, Italia.
Cytogenet Genome Res. 2003;100(1-4):147-53. doi: 10.1159/000072849.
Spinocerebellar ataxia type 6 (SCA6) is one of three allelic disorders caused by mutations of CACNA1A gene, coding for the pore-forming subunit of calcium channel type P/Q. SCA6 is associated with small expansions of a CAG repeat at the 3' end of the gene, while point mutations are responsible for its two allelic disorders (Episodic Ataxia type 2 and Familial Hemiplegic Migraine). Genetic, clinical, pathological and pathophysiological data of SCA6 patients are reviewed and compared to those of other SCAs with expanded CAG repeats as well as to those of its allelic channelopathies, with particular reference to Episodic Ataxia type 2. Overall SCA6 appears to share features with both types of disorders, and the question as to whether it belongs to polyglutamine disorders or to channelopathies remains unanswered at present.
6型脊髓小脑共济失调（SCA6）是由CACNA1A基因突变引起的三种等位基因疾病之一，该基因编码P/Q型钙通道的孔形成亚基。SCA6与该基因3'端CAG重复序列的小扩展相关，而点突变则导致其两种等位基因疾病（2型发作性共济失调和家族性偏瘫性偏头痛）。本文回顾了SCA6患者的遗传、临床、病理和病理生理数据，并将其与其他CAG重复序列扩展的脊髓小脑共济失调以及其等位基因通道病的数据进行了比较，特别参考了2型发作性共济失调。总体而言，SCA6似乎兼具这两种疾病的特征，目前它究竟属于多聚谷氨酰胺疾病还是通道病仍未得到解答。
