Service de Neurologie C, Hôpital Neurologique P. Wertheimer, Bron, France.
Eur Neurol. 2010;64(2):114-6. doi: 10.1159/000315145. Epub 2010 Jul 15.
Episodic ataxia type 2 (EA2) is characterized by paroxysmal bouts of ataxia and progressive cerebellar dysfunction. Other manifestations may also be associated, such as migraine attacks with or without aura, absence epilepsy and mental retardation.
To describe the intrafamilial variability of clinical manifestations of 3 patients harboring a novel CACNA1A point mutation in exon 7 (nucleotide insertion c.1063dupG) typical of EA2 mutation.
All 3 patients presented paroxysmal bouts of ataxia, but age of onset, associated symptoms and symptoms at clinical onset were clearly distinct with hemiplegic migraine attacks in the father, absence epilepsy in one child and mental retardation in the other child.
Typical manifestations of EA2 may be associated and temporally preceded by rare manifestations such as hemiplegic migraine attacks, epilepsy and mental retardation. Moreover, patients sharing a given CACNA1A mutation may present very different phenotypes even within the same family.
发作性共济失调 2 型（EA2）的特征是阵发性共济失调和进行性小脑功能障碍。其他表现也可能与之相关，如伴有或不伴有先兆的偏头痛发作、失神发作和智力迟钝。
描述 3 例携带 CACNA1A 外显子 7 点突变（核苷酸插入 c.1063dupG）的患者的临床表现的家族内变异性，该突变是 EA2 突变的典型代表。
所有 3 例患者均出现阵发性共济失调发作，但发病年龄、伴发症状和首发症状明显不同，父亲表现为偏瘫性偏头痛发作，1 例患儿表现为失神发作，另 1 例患儿表现为智力迟钝。
EA2 的典型表现可能与偏瘫性偏头痛发作、癫痫和智力迟钝等罕见表现有关，并可能在同一家庭中，具有相同 CACNA1A 突变的患者表现出非常不同的表型。
