Somatic Mosaicism in the Aging Brain

Somatic mosaicism is the result of the random mutational damage that occurs to stem cells and progenitor cells, leading to a spread of different mutation patterns throughout the descendant cells making up a tissue. It is thought to be involved in aging, a way for random mutation, different in every cell, to lead to specific dysfunctions occurring throughout a tissue, and potentially prime a tissue for a later combination of mutations that gives rise to cancer. This commentary on recent research discusses somatic mosaicism in the brain, intending to see whether there were differences in neurological disease states, but the findings are more relevant to cancer risk. Mutagenesis occurs in human cells starting from the fertilized egg and continuing throughout life, resulting in somatic mutations. Most somatic mutations are functionally benign and have neither harmful nor beneficial effects on health. In rare cases, they change cell functions and may lead to diseases. Cancer is the most common example of a genetic disorder caused by somatic mutations. In our recent study, we analyzed 131 post-mortem human brains from 44 healthy individuals, 19 with Tourette syndrome, nine with schizophrenia and 59 with autism spectrum disorder. The study reported several interesting findings by whole-genome sequencing of the brains to a depth of over 200X. First, most brains had 20-60 detectable single-nucleotide mutations that likely arose in early development. There were no diffe...
Source: Fight Aging! - Category: Research Authors: Tags: Daily News Source Type: blogs