Researchers in the USA investigated how genetic testing can help in the diagnosis and management of chronic kidney disease in some patients.
The kidneys have many functions including blood filtration, maintaining fluid balance, blood pressure control, red blood cell production, and keeping bones healthy by vitamin D metabolism. In people with chronic kidney disease, these functions gradually decline. At first, patients may have no symptoms, but as the kidney function deteriorates, they may notice swollen ankles, breathlessness, fatigue, dark urine or decreased mental alertness among other symptoms.
Accurate diagnosis of chronic kidney disease is important for patient management
Chronic kidney disease is often the result of high blood pressure or diabetes, but in around 15% of patients the underlying cause is unknown. There are many genetic causes of kidney disease, but these can be difficult to diagnose by traditional medical tests. Accurate diagnosis is important as it affects patient treatment. Researchers at Columbia University, New York investigated how genetic testing can help find the underlying causes of chronic kidney disease. The findings were reported in the New England Journal of Medicine.
The researchers performed DNA sequencing in over 3,300 patients with various types of chronic kidney disease who were participating in two clinical trials – the AURORA study and the Columbia University Medical Center (CUMC) Genetic Studies of Chronic Kidney Disease. In 8.5% of these patients, doctors had not been able to identify the underlying cause of their illness.
Overall, the researchers found a genetic cause for chronic kidney disease in about 9% of the patients tested. DNA testing found a genetic cause in 17% of patients where the cause of kidney disease had not been previously diagnosed by traditional medical tests. The DNA results affected patient treatment in around 85% of the 168 patients who had a genetic diagnosis. Around half the patients were diagnosed with a kidney disorder that affects other organs, and around 1.5% had conditions unrelated to their kidney disease. These findings all had an impact on treatment.
DNA testing is useful when balanced with clinical information
This study shows the usefulness of DNA testing in people with chronic kidney disease. DNA sequencing can help doctors to decide the best treatment. In the future it may help identify patients who will be most likely to benefit from new therapies. However, the researchers cautioned that in another study their team observed that DNA testing in healthy people greatly overestimated the number of kidney-associated genetic problems. Dr. Goldstein, an author on both studies, commented, “Altogether, our research suggests that DNA testing may be most useful when balanced with clinical information.”
- Groopman EE, Marasa M, Cameron-Christie S, et al. Diagnostic utility of exome sequencing for kidney disease. New Engl J Med 2019;380:142-51
- Columbia University Irving Medical Center. 26 Dec, 2018. For patients with kidney disease, genetic testing may soon be routine. https://www.eurekalert.org/pub_releases/2018-12/cuim-fpw122118.php