The The Atlantic article is sensationalized and oversimplified. The scientists are mainstream, and they found that most of the variation between people in compl

The The Atlantic article is sensationalized and oversimplified. The scientists are mainstream, and they found that most of the variation between people in complex traits such as height are due to variation in genes outside core pathways. In other words, there is relatively little variation in genes responsible for growth hormone; instead the cumulative effects of millions of variations in seemingly unrelated genes is what explains differences in height. This is not relevant in the context of gene therapy, where we only change one gene or a small number of genes. From that paper, we would expect that a single change would have a tiny, negligible effect on unrelated genes. Moreover, the initial targets for CRISPR therapies aim to correct mutations. For example, cystic fibrosis is caused by a point mutation in the gene for a mucus protein. CRISPR would be used to restore the genotype that all healthy people have. Since healthy people have this gene, side effects are unlikely. (However, we do expect side effects from other mechanisms such as immune rejection.)