Giunti P, Sweeney M G, Spadaro M, Jodice C, Novelletto A, Malaspina P, Frontali M, Harding A E
University Department of Clinical Neurology, Institute of Neurology, London, UK.
Brain. 1994 Aug;117 ( Pt 4):645-9. doi: 10.1093/brain/117.4.645.
Affected members of 73 families with a variety of autosomal dominant late onset cerebellar ataxias (ADCAs) were investigated for the trinucleotide (CAG) repeat expansion which is found in pedigrees exhibiting linkage to the SCA1 locus on chromosome 6. Most of the families were too small for linkage analysis. The mutation was only found in ADCA type I, in 19 out of 38 such kindreds investigated (50%). It was slightly more common in Italian (59%) than British (50%) families, and was also found in Malaysian, Bangladeshi and Jamaican kindreds. Overall, ADCA type I patients with the expansion had a lower incidence of hyporeflexia and facial fasciculation than those without. The trinucleotide expansion was not found in eight families with ADCA and maculopathy or 24 kindreds with a pure type of ADCA, confirming that these syndromes are genetically distinct. It was also not detected in 12 patients with sporadic degenerative ataxias. DNA analysis for the SCA1 mutation is useful diagnostically in single patients or small families, and can be used for presymptomatic testing where appropriate.
对73个患有各种常染色体显性迟发性小脑共济失调（ADCA）的家族中的患病成员进行了研究，以检测三核苷酸（CAG）重复序列的扩增情况，该扩增在与6号染色体上SCA1位点连锁的家系中被发现。大多数家族规模太小，无法进行连锁分析。该突变仅在I型ADCA中被发现，在所研究的38个此类家族中有19个（50%）存在该突变。在意大利家族（59%）中比在英国家族（50%）中略为常见，在马来西亚、孟加拉国和牙买加的家族中也有发现。总体而言，有该扩增的I型ADCA患者与没有该扩增的患者相比，反射减退和面肌抽搐的发生率较低。在8个患有ADCA和黄斑病变的家族或24个患有单纯型ADCA的家族中未发现三核苷酸扩增，证实这些综合征在遗传上是不同的。在12例散发性退行性共济失调患者中也未检测到该突变。对SCA1突变进行DNA分析在诊断单个患者或小家族时很有用，并且在适当情况下可用于症状前检测。
