一个X连锁遗传的先天性眼球震颤家系基因突变研究

目的 探讨一个X连锁遗传先天性特发性眼球震颤家系的致病基因.方法 为回顾性研究.通过询问病史、临床检查确定遗传表型;进行系谱分析确定遗传方式;通过连锁分析进行致病基因定位;通过基因序列分析发现致病基因突变.结果 经连锁分析,将致病基因定位于Xq25-Xq27 上微卫星位点DXS8044阳DXS1227之间;基因序列分析发现FRMD7基因第8外显子存在两个碱基的缺失.结论 FRMD7基因突变是导致该家系出现疾病的主要原因.

Study of gene mutation in a Chinese family with X-linked congenital nystagmus

OBJECTIVE: To study the disease-causing gene for a Chinese family with X-linked congenital idiopathic nystagmus. METHODS: It was a retrospective study. The phenotype of a Chinese family with congenital nystagmus was identified by investigating the history and the clinical features of each family member. The mode of inheritance in this family was ascertained by the pedigree analysis. Linkage analysis was performed to identify the possible locus harboring the disease-causing gene. Direct DNA sequence analysis was performed to find the mutation responsible for this disease. RESULTS: The positive LOD score was obtained for 10 microsatellite makers on chromosome Xq25-Xq27, and the maximum LOD score with DXS1211 was 3.91. A 2-bp deletion in exon 8 of FRMD7 was detected after direct DNA sequence analysis, which was cosegregated with all patients in this family. CONCLUSION: Congenital nystagmus is a clinically and genetically heterogeneous ocular movement disease. Mutation of the FRMD7 gene is the cause of congenital nystagmus in this family.