NIH Discovers New Vascular Disease, ACDC
Clinical researchers from the National Institute of Health (NIH) have used DNA analysis to discover a rare and debilitating vascular disorder not previously explained in the medical literature. The researchers refer to the condition as ACDC, or arterial calcification due to CD73 deficiency.
ACDC is an adult-onset condition associated with progressive and painful calcification of arteries of the legs. Arteries of the heart remain unaffected. There is also calcium buildup in the joints of the patient’s hands and feet.
“This is the first novel disease discovery identified through the collaborative and interdisciplinary approach employed by clinical researchers in the NIH Undiagnosed Diseases Program," said NIH Director Francis S. Collins, M.D., Ph.D. "This disorder previously baffled the medical field and evaded diagnosis when conventional methods were used."
ACDC has been observed in nine individuals from three unrelated families. The NIH clinical researchers examined members of two families with the arterial calcification disorder as part of the UDP, and identified a third case outside the country. Seven medical cases like those described in this study have been reported in medical journals over the past century, but these previous studies did not include any insights about the molecular basis of the disorder.
Medical evaluations had ruled out rheumatoid arthritis or other joint-related problems. The NIH researchers were able to do a genetic analyses and pinpointed the cause of the condition as mutations, or variants, in the NT5E gene.
Members of two of the three families reported in this study were enrolled and examined as part of the UDP. The patients experienced pain and cramping in the calves, thighs, buttocks and feet due to poor circulation. MRIs and x-rays of the patients' vasculature indicated calcium deposits in artery walls. Peripheral blood vessels compensate to some extent for diminished blood flow in affected arteries, but not always and may result in the need for amputations.