Restoring Vision Loss Caused by Leber Congenital Amaurosis Using Gene Therapy

     The article begins by explaining a unique cause of vision loss in both adults and children. A rare inherited condition called Leber Congenital Amaurosis, more specifically LCA1, is the result of a mutation in the GUCY2D gene. This gene plays a crucial role in producing the proteins that facilitate vision.  LCA1 generally affects people in early childhood. LCA1 affects roughly only 100,000 individuals worldwide. 

    Researchers at the University of Pennsylvania believe they can inject a new unmutated gene into the retinas of adults and children diagnosed with LCA1-- which could improve vision by 100-1,000 times their original vision.  A total of fifteen patients diagnosed with LCA1- twelve children and three adults-- participated in a new study. All subjects had vision equal to or below 20/80 [a normally sighted individual could see an object at eighty feet, whereas these individuals could only see that same object at twenty feet.] 

    A newly developed form of gene therapy called ATSN-101, developed by Atsena Therapeutics, was performed under a phase two trial designed to gauge the treatment's safety and dosages. Hence, the injected therapy was examined under three varying dosages. Three adults received low and medium dosages of ATN-101, once the lower doses were cleared and assessed, three children and three adults received a high dosage of ATN-101. The patients were tested on their ability to navigate through a dimly lit pathway, read eye charts, undergo "light flash" tests performed in dark environments, and other eye performance exams to assess the results.  The end result was an improvement in vision nearly immediately, usually, within a month, improvements were seen, and treatments lasted around a year. Two out of the nine patients' sight improved by 10,000-fold compared to their sight prior to treatments. Any side effects observed using the therapy were generally related to the surgery itself that was used to implant the gene therapy; such as temporary acute hemorrhages in the eye and or temporary eye inflammation. 

I found this article interesting as I had never heard of the condition Leber Congenital Amaurosis or knew what caused this disease; a mutation in a specific gene called LCA1.  This article piqued my interest from the beginning, and after skimming it, I grew more interested in the topic.  I found it particularly interesting when the authors mentioned that a team of researchers had prior success applying gene therapy to correct another form of Leber Congenital Amaurosis caused by a mutation in another gene referred to as CEP290.  Overall, I found the research in this article both enlightening and hopeful, not only as a viable treatment for individuals with this condition but as a reaffirming promise for the field of gene therapy in treating other conditions/diseases in medicine.