New genetic testing recommendations could help improve accuracy of kidney disease diagnosis

July 26, 2024 

By Ethan Chupp, UNC Gillings School Communications Fellow 

Chronic Kidney Disease (CKD) affects over 37 million Americans and can have a variety of causes. Many cases of CKD have genetic causes, especially in children. Nevertheless, genetic testing for CKD has lagged behind other medical fields. Many nephrologists say they lack enough information to identify which patients will most benefit from genetic testing, select which genetic test to use, or interpret and disclose results to patients.  

Dr. Nora Franceschini

A new report from a National Kidney Foundation (NKF) Working Group provides recommendations to advance the use of genetic testing for kidney diseases. The group was co-chaired by Nora Franceschini, MD, MPH, professor of epidemiology at the UNC Gillings School of Global Public Health, along with Ali Gharavi, MD, of the Columbia University Vagelos College of Physicians and Surgeons. The panel included other experts in genetics, nephrology, kidney pathology, genetic counseling and ethics, and drew on the perspective of patients. 

The Working Group sought consensus on the recommendations through a multi-round standard voting system, known as the Delphi method. 

“The intent is to facilitate the implementation of already well established and newly developed clinical genetic tests by addressing provider barriers and patients concerns to the use of these tests, and foster more research in the field to use genetic testing in clinical care,” said Franceschini. 

The final report, featuring 56 recommendations and charts to help decide which patients should receive which tests, is now published in the American Journal of Kidney Diseases. 

Genetic testing has many potential benefits for CKD, most notably when it comes to diagnosing or screening for kidney diseases. Traditionally, CKD is diagnosed based on symptoms and blood or urine tests that determine kidney function. A more precise diagnosis from genetic testing can help health care workers identify the right level of care and services for the patient, including avoiding improper treatments. Genetic tests are also less invasive than other advanced diagnostic techniques like kidney biopsies. Different types of CKD can have significantly different prognoses, and genetic testing can help determine the likely progression of the specific patient. With genetic information, patients will have more information on whether family members or their children may develop the same condition.  

The panel provided recommendations for genetic testing of single-gene disorders manifesting in children or adults, but also discussed genetic testing for the APOL1 gene.

“The nephrology community has a great example of a gene called APOL1 that is associated with CKD, but only a small proportion of people who inherit the risk variants develop disease. There is currently still controversy on the clinical utility of genetic testing of APOL1, and there are social, ethical and legal considerations for testing,” said Dr. Franceschini. 

However, genetic testing can carry downsides. Testing can be expensive, and the cost has to be balanced with a potential upside. One risk of testing patients without symptoms is that it may lead to the discovery that they are at risk for a type of CKD for which there is no treatment. Results can also be inconclusive. Furthermore, most genetic research has studied populations of European ancestry, and there are significant knowledge gaps about the genetic variation in underrepresented populations.  

The recommendations from this Working Group are intended to help nephrologists identify patients who would benefit from testing, explain the rationale to the patient and family members, and provide follow-up for interpretations of results.  

Franceschini emphasized that these recommendations are not set in stone.

“They are based on the current state of the field. Hopefully, the research will evolve and more testing will be available in the future as the knowledge of the genetic diseases advances.” 

For example, the current recommendations primarily cover kidney diseases from a single-gene origin. The group was interested in a “score” that estimates a patient’s risk based on many genes. More research is needed before these scores can be used in practice.  

The field of genetic testing for chronic kidney disease is advancing quickly. This report provides a tool to help doctors and patients make the best use of these new tools for diagnosis and screening of kidney diseases. 

Read the full report here. 

Contact the UNC Gillings School of Global Public Health communications team at sphcomm@unc.edu.