Do the manipulations by spirit meddler attachments contribute to the phenomenon of somatic mosaicism, and is that a factor in perturbing function of the brain, wherein no two neurons are genetically alike?

The spirits meddlers do not do this directly, but they can work to put people in harm's way and this can be orchestrated to happen by the overseers in the form of the extraterrestrial spirits commanding them. So there can be a parlay of manipulations to get a person in just the wrong spot at the wrong time to receive a huge dose of energetic perturbation, for those being targeted specifically. As a general rule, they work through consciousness itself to stir up memories of past failure and painful episodes to frighten the subconscious, and distract and subdue it to create, eventually, a state of hopelessness and surrender. This further erodes the self-protection mechanisms and leaves the person as a sitting duck for any and all interlopers to simply march in and siphon off some energy. But the genetic manipulation, per se, is not likely to happen through this means.