Encoded in our DNA are thousands of genes. Working together, they determine all sorts of physical attributes—from eye color and blood type to the number of limbs we have—and much, much more.
It’s also true that defective genes can sometimes make us sick.
Scientists have worked for decades on ways to repair or replace faulty genes to prevent or even cure genetic diseases.
Dr. Krysztof Bankiewicz, professor of neurological surgery at Ohio State University, says that work is finally coming to fruition.
Matthew: What we're talking about is gene therapy. In the most basic terms, how does gene therapy work?
Dr. Bankiewicz: It's a novel way of delivering therapeutics to the body and specifically within the brain. It is a way where we can, through the genetic manipulation of vehicles that we can inject into the brain, program the cells within the brain to secrete a therapeutic agent. And specifically, if we can identify genetic mutations and a number of disorders that are affecting the population at large, we can replace the defective gene with a gene that is supposed to be there.
Matthew: You and your team have developed a new platform for delivering gene therapy to specific areas of the brain. How was this an advancement over previous technologies?
Dr. Bankiewicz: The big issue that we have with the delivery of gene therapy, specifically to the brain, is that the particles that we have to use that encapsulate the genetic material cannot pass into the brain because of what we call the blood brain barrier. It protects us from a lot of toxins and other elements such as viruses and bacteria from entering the brain. So, this is really very challenging in terms of being able to deliver gene therapy to the brain. So the technology that we are offering right now to patients, based on the clinical trials that we are running at OSU, multiple different disorders such as Parkinson's, Alzheimer's, multiple system atrophy (MSA) … allows us to place the patient in the MRI scanner with a tiny little cannula under direct control of the imaging, and then we inject the gene therapy to a very precise place within the brain.
Matthew: One of the patients you've been able to help with this technology is a 9-year-old girl from Omaha, Nebraska, named Delilah Ramirez. She suffers from a rare genetic disorder called aromatic L-amino acid decarboxylase (AADC) deficiency. Children with AADC deficiency are missing the enzyme that produces dopamine and serotonin in the central nervous system. These children can't coordinate the movements of their head, face and neck, and often struggle to reach certain childhood development milestones. How much of a difference has gene therapy made in Delilah and children like her?
Dr. Bankiewicz: It’s huge. Suddenly they're able to sit upright and that is huge because at the same time, they may be able to start eating now. So that's a that's a huge, huge improvement for them. Then after that they're able to sit, able to stand, able to start walking. So, these are the motor components. On top of it, we targeted the part of the brain that controls their emotions as well. And now they're happy. They start smiling. They can interact with the environment. Some of these children even begin to speak. And many of them are working now without assistance within two to three years of the gene therapy. So, they're catching up very quickly. And we’re incredibly happy for them and their families that actually are celebrating their new birthdays, which is the date of the gene therapy surgery at OSU.
