Deleted 4977-bp mitochondrial DNA mutation is associated with sporadic amyotrophic lateral sclerosis: A hospital-based case-control study

We investigated the relationship between the most common 4977‐bp deleted mitochondrial DNA (mtDNA) mutations and the occurrence of sporadic amyotrophic lateral sclerosis (ALS). Primer‐shift and quantitative polymerase chain reaction (PCR) were used to determine the 4977‐bp deleted mtDNA in the muscle specimens from 36 patients with sporadic ALS and 69 age‐matched controls with other neuromuscular disorders. We found that the 4977‐bp deleted mtDNA mutations were significantly higher in the ALS patients than controls in both frequency (50.0% vs. 8.7%, P < 0.01) and amount (0.35 ± 0.53% vs. 0.085 ± 0.35%, P < 0.05). Subjects with, rather than without, deleted mtDNA were at a significantly higher risk for having ALS after adjustment for age and sex. Moreover, male subjects had a higher risk than female subjects of having sporadic ALS. This study suggested that 4977‐bp deleted mtDNA is significantly associated with the occurrence of sporadic ALS. Muscle Nerve 28: 737–743, 2003