一个遗传性脊髓小脑共济失调大家系的连锁分析

目的检测一遗传性脊髓小脑共济失调家系的遗传缺陷基础。方法收集湖南地区一遗传性脊髓小脑共济失调家系,对患者的临床表型进行评估。采集家系成员48人（包括患者8人）外周静脉血提取基因组DNA,对候选染色体区域选取合适的微卫星标记,采用多重PCR和电泳方法进行基因组扫描,数据经Linkage软件包进行连锁分析以对该家系进行基因定位,以确定疾病相关基因所在的染色体区域。结果两点间连锁分析结果显示,该家系在脊髓小脑共济失调遗带瘟童SCAl、SCA27SCA3、SCA57SCA67SCA77SCA87SCAl07SCAl,？SCAl27SCAl37SCAl47SCAl57SCAl67SCAl7、SCA20、SCA27、SCA28、SCA31、DRPLA处的最大LOD值仅为0．49,提示该家系致病基因与这些位点无连锁关系。结论排除该家系与目前已知的20个常染色体显性小脑共济失调相关染色体位点的连锁关系,提示可能存在其它未知的SCAs位点。

Genetic study of a heredity spinocerebellar ataxia pedigree in Hunan province.

Objective： To detect the genetic defect in a heredity spinocerebellar ataxia pedigree. Methods： Patients from the SCA pedigree underwent careful clinic evaluation. Genomic DNA was extracted from peripheral leukocytes and amplified using touch - down PCR for gene scanning. Two - point linkage analysis was performed to define the responsible gene to relevant chromosome region. Re- sults ： Positive linkage results were not obtained, with the maximum LOD score was only 0.49, which exclude the linkage between the mutant gene in this pedigree and the known SCAs loci. Conclusion： This study showed that the gene responsible for this SCA pedigree didn＇t locate on the known SCAs loci, which suggest other genes may play the roles in SCAs.