Lin Yan, Zheng Jia-Yong, Jin Yan-Hui, Xie Yan-Chen, Jin Zi-Bing
Department of Neurology, Second Affiliated Hospital of Wenzhou Medical College, Zhejiang 325000, China.
Neurosci Lett. 2008 Mar 28;434(2):230-3. doi: 10.1016/j.neulet.2008.01.077. Epub 2008 Feb 13.
Spinocerebellar ataxia type 7 is a rare autosomal dominant cerebellar ataxia (ADCA). Herein, we describe the molecular and clinical findings in patients within six generations of a large Chinese family with spinocerebellar ataxia. To identify the genetic cause(s), 4 affected patients and 26 asymptomatic relatives were recruited for the study. Molecular screening of the SCA1 and SCA7 genes was carried out by subcloning and direct PCR-sequencing methods. Both neurological and ophthalmic examinations were performed to investigate the clinical characteristics of the disease. The patients had typical cerebellar ataxia, achromatopsia and macular degeneration, and displayed a rare phenotype manifesting as a combination of cerebellar ataxia and craniocervical dystonia. Mutational analysis of the SCA7 genes demonstrated expanded CAG-repeats in the four patients. In conclusion, we identified expanded CAG-repeats in the SCA7 gene within members of a large Chinese family with spinocerebellar ataxia. The defined phenotypic characteristics of the patients may be helpful for clinical diagnosis and genetic typing of new patients.
7型脊髓小脑共济失调是一种罕见的常染色体显性小脑共济失调（ADCA）。在此，我们描述了一个患有脊髓小脑共济失调的中国大家庭六代患者的分子和临床研究结果。为确定遗传病因，招募了4名患病患者和26名无症状亲属参与研究。通过亚克隆和直接PCR测序方法对SCA1和SCA7基因进行分子筛查。同时进行神经学和眼科检查以研究该疾病的临床特征。这些患者具有典型的小脑共济失调、色盲和黄斑变性，并表现出一种罕见的表型，即小脑共济失调和颅颈肌张力障碍的组合。对SCA7基因的突变分析显示，这4名患者中存在CAG重复序列扩增。总之，我们在一个患有脊髓小脑共济失调的中国大家庭成员中鉴定出SCA7基因中的CAG重复序列扩增。患者明确的表型特征可能有助于新患者的临床诊断和基因分型。
