一个肌萎缩侧索硬化家系的SOD1基因突变

Identification of the mutation of SOD1 gene in a familial amyotrophic lateral sclerosis

SHI Shu-gui, LI Lu-si, CHEN Kang-nin, LIU Xing. (Department of Neurology, Southwest Hospital, Third Military Medical University, Chongqing, 400038 P.R. China.) Objective To identify the mutation of Cu/Zn superoxide dismutase ( SOD1) gene in an amyotrophic lateral sclerosis (ALS) family with unique phenotype. Methods Five exons of SOD1 gene were amplified by PCR.The differences of these products were analyzed by PCR-single strand conformation polymorphism and visualized by silver staining. Results Abnormal bands were found in exons 2 and 5 of SOD1 gene in several familial members. DNA sequence analysis verified that a base pair insertion occurred in the codon area of exon 2 and in the intron area of exon 5. And the insertion mutation of exon 2 led to a frameshift mutation and premature stop. It is a new type of SOD1 mutation which may be associated with familial amyotrophic lateral sclerosis. Conclusion Insertion mutation of exon 2 may be responsible for the disease of an ALS family in Chongqing.