Genome-wide quantification of rare somatic mutations in normal human tissues using massively parallel sequencing

Significance While we age, our body accumulates random somatic mutations. These mutations spontaneously arise from endogenous and exogenous sources, such as DNA replication errors or environmental insults like smoking or sunlight. Direct measurement of rare mutations could help us understand the role of somatic mutations in human aging, normal biology, and disease processes. Here, we develop the bottleneck sequencing system (BotSeqS) as a simple genome-wide sequencing-based method that accurately quantitates nuclear and mitochondrial mutational load in normal human tissues. We demonstrate that mutation prevalence and spectrum vary depending on age, tissue type, DNA repair capacity, and carcinogen exposure. Our results suggest a varied landscape of rare mutations within the human body that has yet to be explored.