The 'Naha' are very advanced on the treatment of genetic diseases and conditions. Philosophically they are inclined not to alter one's genetic make up even if it means allowing a longer term problem persist. The reasoning is that to cure 'all genetic diseases and conditions' would result in a reduction of the 'genetic bandwidth' of the human race. Where ever possible the 'Naha' rely on the 'katim' to provide corrective medicine to mitigate the effects of a faulty genome.
Another line of reasoning is that although a gene, or combination of genes, may raise the likely hood of health problems, the production of altered proteins may effect of the individual (i.e. their creativity and/or originality). The 'Naha' are aware they can reproduce most human thought processes in simulations and have even implemented them in some robotic devices, but it is the variability of the human race that is considered the keystone of future progress so a reduction in its possibilities is not considered to be a good idea.
Some genetic conditions have been eradicated (subject to their re-appearance through natural mutation) and some genetic conditions can be so severe that genetic manipulation is advised, but this is very rare with only very few 'nahumar' offering such services
The 'Naha' have the ability to target all nearly all cells in the human body and make edits to the genome. They are also able to create chimera where changes to the host's genome can be made to reduce the effect of faulty genes.