The researchers looked at a type of genetic change called copy number variants, which refers to the number of copies of genes in human DNA. (sciencedaily.com)
Scientists discovered that when this occurs, a DNA repair process employed within human embryos activates to fix the broken gene, using the normal copy of the gene as a template. (health.com)
Moreover, cells can dial gene expression up or down, adjusting to produce anywhere from a few working copies of a gene to several thousand. (sciencedaily.com)