Re “What genes can’t fix’’ (Ideas, June 4): Reading Jim Kozubek’s Globe feature on the muted impact of Crispr genome editing technology certainly upended some of my preconceptions. Regardless of this, Kozubek’s point applies exclusively to complex, mainly neurological, disorders with polygenic etiologies.

He omits the fact that not all genetic disorders are of this type; instead, some are simpler and more understood. These genetic diseases are not few and far between, as Kozubek would imply. Sickle cell disease, cystic fibrosis, Duchenne muscular dystrophy, Huntington’s disease, and other conditions are all caused by issues with individual genes well within Crispr’s editing grasp. A 2015 Harvard study tested Crispr treatment for rats with a single mutant gene predisposing retinitis pigmentosa and found success in restoring their degenerating vision. Unlike Kozubek’s examples of schizophrenia and autism, these disorders have no assessed epigenetic links.

Because of how defined and localized these diseases are, Crispr is likely a viable option for treatment, churning with potential like the retinitis pigmentosa trials. If so, then the argument that “genetics is not about to lead to a paradigm shift in public health’’ is erroneous. Perhaps Crispr may not be able to effectively treat complex neurological issues, but that cannot discount its groundbreaking applications in other disease treatment.

Simon Levien

Sparta, N.J.

The writer is a student leading an initiative to bring educational Crispr biotechnology gene editing kits to Sparta High School. He is a science blogger for The Pacific Tribune.