NEW FINDINGS — THERAPEUTICS
Online resource helps healthcare workers treat genetic diseases With the advent of whole genome sequencing and other genom- ic testing, the cause for many genetic disorders are being rapidly discovered. One geneticist acknowledged this and set out to create a resource that serves as a convenient, readily available starting point for health care providers looking for treatment information for genetic disorders. The resource, called Rx-Genes (Rx-genes.com), provides information about current treatments and treatments that are in clinical trials for genetic disorders. The website and corresponding mobile app currently contain more than 630 disease entries that include references to disease infor- mation and treatment guidance, a brief summary of treatments, the inheritance pattern, disease frequency, nonmolecular confirmatory testing, and a link to experimental treatments. Existing entries are continuously updated, and new entries are added as new treatments appear in the literature. Rx-Genes is a promising tool that helps healthcare providers more easily and efficiently access the newest information about genetic disorders. REFERENCE: Bick D. et al., An online compendium of treatable genetic disorders. Am J Med Genet . (2021) 187C:48-54. DOI: 10.1002/ajmg.c.31874. Rx-genes.com HudsonAlpha faculty researcher David Bick MD contributed to this work. During the clinical trial, although researchers injected the gene thera- py into one eye, participants reported improved vision in both eyes. By performing additional experiments in monkeys, the researchers found that even if they injected the gene therapy into one eye, it was later found in both eyes. It could also be seen in their optic nerves which suggests that it had travelled down the optic nerve of the treated eye, passed into the other optic nerve where the two nerves cross over, and moved into the untreated eye. While it is promising that the therapy seems to improve vision, it still requires more testing for safety and efficacy. The discovery that it travels between eyes has implications for safety, as well as for how the therapy’s effectiveness is measured, because such trials usually compare the treated eye’s vision with that of the untreated eye. In fu- ture studies the researchers will need to compare individuals given the gene therapy injection with individuals who receive placebo injections. REFERENCE: Yu-Wai-Man P. et al., Bilateral vision improvement with unilateral gene therapy injection for Leber hereditary optic neuropathy. Sci Transl Med . (2020) 12(573):eaaz7423. DOI: 10.1126/scitranslmed.aaz7423. Gene therapy for rare form of blindness travels between eyes Gene therapy for a rare form of blindness improved vision in the majority of patients that received it during a recent trial. However, the trial was deemed unsuccessful because the patients surprisingly also reported improvements in vision in their untreated eye. The treatment was designed for the rare, inherited form of blindness called Leber’s hereditary optic neuropathy. The disease is caused by a mutation in one of the genes inside mitochondria, the energy-pro- ducing structures inside cells. The mutation disrupts the mitochondria and causes cells in the retina to stop working or die. These cells are required to relay visual information from the eyes to the brain. Gene therapy treatment aims to correct the faulty mitochondrial DNA gene. A harmless virus containing the gene is injected into the eye, where it is taken up by retinal cells. These cells start making the pro- tein encoded by this gene, which passes into their mitochondria and helps preserve their remaining retina.
Successful treatment for sickle cell anemia
Gene therapy holds promise for treating a wide range of diseases, but historically it has seen more failures than successes. Howev- er, within the last decade the field has begun stacking up some impressive wins. Recently, several patients with a blood disorder called sickle cell disease have found relief from their excruciating symptoms thanks to a clinical trial using CRISPR-based gene therapy. Sickle cell disease is an inherited blood disorder caused by mutations that affect the production or structure of hemoglobin, the protein that carries oxygen in red blood cells. The defective hemoglobin turns red blood cells into deformed, sickle shaped cells that get stuck inside blood vessels and clog up blood flow. This causes excruciating attacks of pain, organ damage, and often premature death.
Early clinical trials for CRISPR-based gene therapy are showing promise for individuals with sickle cell disease. CRISPR is used to edit stem cells and allow them to produce a slightly different type of hemoglobin called fetal hemoglobin which is normally inactivated after birth. Bone marrow stem cells are removed from the affected individuals and the gene that turns off fetal hemo- globin production is disabled using CRISPR. The edited cells are One year after her treatment, the first U.S. patient to receive the gene therapy has not had any severe pain attacks and has not required any emergency room treatments, hospitalizations, or blood transfusions. Nearly every red blood cell in her body produces some level of fetal hemoglobin and about 46% of her total hemoglobin is fetal. The company that produces the gene therapy also reported favorable results on seven additional sickle cell patients and fifteen patients with a related condition called beta thalassemia. Although these treatments are still in early trials, the results look promising and could one day bring relief to other individuals suffering from these types of blood-based genetic disease. transfused back to the patient and the now active fetal hemoglobin can carry oxygen throughout the body. REFERENCES: www.npr.org/sections/health-shots/2020/06/23/877543610/a- year-in-1st-patient-to-get-gene-editing-for-sickle-cell-disease-is-thriving. And “Vertex and CRISPR Therapeutics Present New Data in 22 Patients With Greater Than 3 Months Follow-Up Post-Treatment With Investigational CRISPR/Cas9 Gene-Editing Therapy, CTX001™ at European Hematology Association Annual Meeting” 11 June, 2021. www.businesswire.com/news/home/20210611005069/en/ Vertex-and-CRISPR-Therapeutics-Present-New-Data-in-22-Patients-With-Great- er-Than-3-Months-Follow-Up-Post-Treatment-With-Investigational-CRISPRCas- 9-Gene-Editing-Therapy-CTX001%E2%84%A2-at-European-Hematology-Associa- tion-Annual-Meeting. Accessed 31 August 2021. Press Release.
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