Experienced Nephrologists that consider every detail to build the best individualized treatment plan for their patients

Our Nephrologists specialize in managing a broad range of kidney diseases, electrolyte disorders, hypertension (high blood pressure), kidney transplantation evaluation and aftercare, in addition to all forms of dialysis. Each physician has extensive experience and is board certified in the subspecialty of Nephrology by the American Board of Internal Medicine.

Many of our doctors serve on various hospital committees and as the medical directors for many hemodialysis units in Northern Virginia. Our active participation and leadership ensures we drive and enforce important standards while also enabling us to stay at the forefront of our field.  Our Nephrologists have also been recognized as Top Doctors in the Washingtonian Magazine as well as other local publications.


Robert C. Mackow, M.D.

Dr. Mackow joined the practice in 1988 after serving as an Assistant Professor of Medicine at  Georgetown University. He has been practicing Nephrology for over 30 years and was an instrumental contributor in the foundational development of the INOVA Kidney Transplant Program. He has been recognized as one of Northern Virginia’s Top Doctors by his peers year after year. He has a special interest in Hemodialysis and Transplantation. In his spare time he is an avid photographer and golf enthusiast.

Ali R. Assefi, M.D., MRCP

Dr. Assefi completed his Nephrology training at Georgetown University in 1989 and joined NANV in 1991. Along with Dr. Mackow, he was instrumental in growing NANV into the largest Nephrology practice in Northern Virginia. His commitment to patient care led him to serve as the Nephrology Section Chief for Inova Fairfax Hospital as well as serve on the Medical Executive Committee. He is also a devoted mentor with numerous teaching awards during his tenure as a Clinical Assistant Professor of Medicine at Virginia Commonwealth University.

Franco Musio, M.D., FACP

Dr. Musio has been with NANV since 1998. He completed his Nephrology training at Walter Reed National Military Medical Center and served on the faculty for three years. His military experience reflects his approach with patients today – dedication and passion for helping and supporting others. He has  served on the INOVA Fairfax Medical Executive Committee as well as the National Kidney Foundation Distinguished Advisory Board.  Currently, he is the Nephrology Section Chief at INOVA Fairfax Hospital. In his spare time, he is a devoted student of the martial art of Hapkido. He currently lives in Oakton with his wife and son

Jenny J. Nazzal, M.D.

Dr. Nazzal has been with NANV since 2002 and has been practicing for 34 years. She completed her Nephrology training at the Washington Hospital Center and stayed in the area to serve the area that she loves. Dr. Nazzal has a special interest in genetic/cystic kidney diseases. She lives in Great Falls with her husband and sons and she enjoys cooking and traveling in her spare time.

Khalid M. Shumburo, M.D.

Dr. Shumburo has been with NANV since 2006 after completing his Nephrology training at the George Washington University. He has served as the Nephrology Section Chief at INOVA Alexandria Hospital and oversaw the policies and procedures aimed to ensure the best care for our patients. He is a devoted father to two daughters and in his spare time he enjoys grilling, hiking and biking.

Kourosh Dibadj, M.D.

Dr. Dibadj completed his Nephrology training at the University of Florida. During this time, his research helped develop a test, which is now commercially available for the BK virus in kidney transplant patients. He joined NANV in 2007. His continued passion for innovation led him to develop "LyteAid", a low calorie drink designed for kidney patients. In  addition to general nephrology, he has a special interest in the diagnosis and management of Glomerular diseases. He resides in Vienna with his wife and daughter.

Gregory Wang, M.D.

Dr. Wang has been with NANV since 2008 after completing his Nephrology training at Emory University.  Dr Wang was drawn to Nephrology because of the long term relationships formed with patients. Dr. Wang believes that an equal partnership between the patient and doctor  is the foundation to a long-term treatment plan. Dr. Wang has published research on the effect of kidney transplantation in patients with heart failure. In addition, he has a special  interest in dialysis access and has additional training in Interventional Nephrology. In his free time, he enjoys volleyball and spending time with his daughter.

Ahmad S. Mirkhel, M.D.

Dr. Mirkhel joined NANV in 2011 and has been practicing for over 14 years. Prior to completing his Nephrology training at Georgetown University, he worked as a Hospitalist at INOVA Fair Oaks Hospital. He is an accomplished speaker having presented at several national conferences . He is active in the community and has volunteered at the Loudoun Free Clinic. He lives in Ashburn with his family and enjoys following politics.

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Misbah Zaheer, M.D.

Dr. Zaheer joined NANV as an Associate in August of 2016. After completing her residency in Internal Medicine, she served as a hospitalist at Georgetown University Hospital. During her Nephrology fellowship at Georgetown University she served as the Chief Nephrology Fellow. Dr. Zaheer has published scholarly articles on Hypertension, Chronic Kidney Disease, and Antibody Mediated Rejection in Kidney Transplants. She also contributed a book chapter on Hypertension and Atherosclerosis. She lives in Fairfax, Virginia with her husband and two children.


Kevin T. Harley, M.D.

Dr. Harley joined NANV in 2018.  He is originally from Southern California and completed his nephrology training at the University of California, Irvine.  Dr. Harley spent a number of years on the clinical faculty at the same institution.  He has a passion for teaching, and has served as a faculty program director for nephrology fellow training.  He has co-authored a number of scholarly articles on topics in nephrology, and has given many lectures at various institutions.  Dr. Harley lives in Falls Church.  In his free time, he enjoys running and cycling around Northern Virginia.