New Guidance on Genetic Testing for Kidney Disease

More Education Needed; Many Barriers

The authors acknowledged that nephrologists generally receive little education in genetics and lack support for interpreting and discussing results.

“Nephrologists should be provided with training and best practice resources to interpret genetic testing and discuss the results with individuals and their families,” they wrote, adding that there’s a need for genomic medicine boards at academic centers that would be available to help nephrologists interpret results and plot clinical management.

The group did not, however, cite some of the other barriers to adoption of testing, including a limited number of sites offering testing, cost, and lack of insurance coverage for the diagnostics.

Medicare may cover genetic testing for kidney disease when an individual has symptoms and there is a Food and Drug Administration–approved test. Joseph Vassalotti, MD, chief medical officer for the NKF, said private insurance may cover the testing if the nephrologist deems it medically necessary, but that he usually confirms coverage before initiating testing. The often-used Renasight panel, which tests for 385 genes related to kidney diseases, costs $300-$400 out of pocket, Dr. Vassalotti told this news organization.

In a survey of 149 nephrologists conducted in 2021, both users (46%) and nonusers of the tests (69%) said that high cost was the most significant perceived barrier to implementing widespread testing. A third of users and almost two thirds of nonusers said that poor availability or lack of ease of testing was the second most significant barrier.

Clinics that test for kidney genes “are largely confined to large academic centers and some specialty clinics,” said Dominic Raj, MD, the Bert B. Brooks chair, and Divya Shankaranarayanan, MD, director of the Kidney Precision Medicine Clinic, both at George Washington University School of Medicine & Health Sciences, Washington, DC, in an email.

Testing is also limited by cultural barriers, lack of genetic literacy, and patients’ concerns that a positive result could lead to a loss of health insurance coverage, said Dr. Raj and Dr. Shankaranarayanan.
 

Paper Will Help Expand Use

A lack of consensus has also held back expansion. The new statement “may lead to increased and possibly judicious utilization of genetic testing in nephrology practices,” said Dr. Raj and Dr. Shankaranarayanan. “Most importantly, the panel has given specific guidance as to what type of genetic test platform is likely to yield the best and most cost-effective yield.”

The most effective use is “in monogenic kidney diseases and to a lesser extent in oligogenic kidney disease,” said Dr. Raj and Dr. Shankaranarayanan, adding that testing is of less-certain utility in polygenic kidney diseases, “where complex genetic and epigenetic factors determine the phenotype.”

Genetic testing might be especially useful “in atypical clinical presentations” and can help clinicians avoid unnecessary expensive and extensive investigations when multiple organ systems are involved, they said.

“Most importantly, [testing] might prevent unnecessary and potentially harmful treatment and enable targeted specific treatment, when available,” said Dr. Raj and Dr. Shankaranarayanan.

Dr. Franceschini and Dr. Shankaranarayanan reported no relevant financial relationships. Dr. Raj disclosed that he received consulting fees and honoraria from Novo Nordisk and is a national leader for the company’s Zeus trial, studying whether ziltivekimab reduces the risk for cardiovascular events in cardiovascular disease, CKD, and inflammation. He also participated in a study of Natera’s Renasight, a 385-gene panel for kidney disease.

A version of this article first appeared on Medscape.com.