Precision Medicine Fellow Brings Genetics to Pediatric Nephrology

Pediatric nephrologists are rare, with only around 1,100 nationwide. Pediatric nephrologists who specialize in genetics are even harder to find, even though there are more than 300 genetic disorders associated with kidney disease — and likely many more which have yet to be discovered. As the first precision medicine fellow at the University of Colorado School of Medicine and Children’s Hospital Colorado, pediatric nephrologist Sarah Nelson-Taylor, MD, PhD, is focusing her research on the important intersection between kidney disease and inherited gene disorders.

Previously, Dr. Nelson-Taylor's research looked at the genetic changes that occur in the kidney in diseases like nephrotic syndrome and focal segmental glomerular sclerosis, or FSGS. With support from the fellowship, she plans to leverage this background to work on gene panels, which are intentional groupings of genes that make it easier for providers to test for a wide array of potential variations that could signify specific conditions. Dr. Nelson-Taylor's focus on pediatric gene panels is an important distinction, since most gene panels are made for adults and may not accommodate the many potential genetic markers driving kidney disease in children.

"I'm going to be developing panels that we can use in house, and we can hopefully make them available to the larger pediatric nephrology community,” Dr. Nelson-Taylor says. “By doing that kind of work, we will have access to the genetic testing that we've done on lots of patients and develop and discover new genetic markers for kidney disease for patients who don't fit into our classic genetic diseases.”

Understanding genetic markers for kidney disease

One example demonstrating the importance of genetic testing in pediatric nephrology involves Focal Segmental Glomerulosclerosis (FSGS), a disease where the glomeruli, a part of the kidneys responsible for filtering waste, develop scar tissue. Without dialysis or transplant, FSGS can lead to kidney failure.

“There is a subset of patients with FSGS, particularly in our Black and African American patients, who have mutations in a gene called APOL1," Dr. Nelson-Taylor says. “We've known for about 10 years that this can predispose kids to kidney disease and progress to kidney failure within a relatively short period of time."

A drug called Inaxaplin, in its third phase of clinical trials, is being tested to help slow the progression of kidney disease in this population. This case highlights why it’s important for kids with kidney disease to have access to high quality testing, because identifying the genetic cause of their disease may open the door for targeted therapies that are or may become available.

“If you don't have genetic testing on a patient with FSGS who has this APOL1 mutation, you would never know that they would be a candidate for this medication,” Dr. Nelson-Taylor says. “It's really important that we understand what is causing kids' kidney disease so that if there is a treatment in the future that they're eligible for, we know it.”

Furthering access to genetics in pediatric nephrology

Despite the importance of genetic understanding in supporting patients with kidney disease, there aren’t enough genetic counselors, or providers trained in genetics, in pediatric care across the country. “Right now, we're kind of limited in our access to genetic counselors and getting our kids in with genetics just because the demand is so high,” Dr. Nelson-Taylor explains. “If we can somehow bring that in-house by having someone like myself with training in genetics and precision medicine, we decrease the burden on the genetics clinics but also increase the access to care for our patients.”

Dr. Nelson-Taylor understands firsthand the kinds of challenges facing families with genetic disorders. “Just after I made the plans to join this fellowship, my third child was born and has a rare genetic condition,” Dr. Nelson-Taylor says. “This has really highlighted to me the need for providers who understand both how to treat and how to diagnose complicated genetic conditions.”

Dr. Nelson-Taylor's daughter requires care across dermatology, genetics and neurology, which has also underscored the importance of multidisciplinary care for kids with genetic conditions. “Nephrology is just my particular interest, but I think it really drives home the importance of training pediatric subspecialists in genetics and precision medicine.”