It is rare that a new disease stakes a claim in our human lives, but a new one has surfaced named ACDC. This newly discovered ailment restricts a person’s arteries below the waist in the lower limbs via calcium build up along arterial walls and joints. This is caused by genetic mutations in the NT5E, or CD73 (Cluster of Differentiation 73) gene, and adds to the breakthroughs already documented in genetic research 2011. Humans consist of approximately 350 of these said clusters.

Only nine unrelated persons are known to have the disorder, so far.

NIH Director Francis S. Collins, M.D., Ph.D. explains:

“This is the first novel disease discovery identified through the collaborative and interdisciplinary approach employed by clinical researchers in the NIH Undiagnosed Diseases Program. This disorder previously baffled the medical field and evaded diagnosis when conventional methods were used.”

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.

The NIH Undiagnosed Diseases Program, under way since May 2008, is an initiative jointly led by the NHGRI, the NIH Clinical Center and the NIH Office of Rare Diseases Research that draws upon numerous areas of medical and basic research specialization within the NIH. More than 200 medical cases have been enrolled from among more than 1,200 sets of patient records submitted by patients seeking answers to mysterious disorders. The program’s goal is to provide answers to patients with difficult-to-diagnose conditions and to advance medical knowledge about both rare and common diseases.

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.

So far, one patient has been treated with surgeries to reroute blood flow through alternate vessels, as well as a joint amputation in the foot. Peripheral blood vessels compensate to some extent for diminished blood flow in affected arteries.

Manfred Boehm, M.D. continues:

“The diagnosis of this faulty gene is the first molecular description of this disorder. In addition to providing insight for this unique patient group and their physicians, the study has placed this condition among disorders it resembles, adding to our knowledge of vascular biology.”

In one of the families with five affected siblings, clinical researchers suspected a recessive inheritance, in which offspring receive two copies of a gene variant, one from each parent that produces disease symptoms only when combined. The researchers analyzed DNA from all members of the family to compare the parents’ DNA to that of their affected children. This allowed researchers to detect genomic regions where the siblings’ DNA contained two copies of a particular DNA segment compared to their parents’ DNA, which contained just a single copy.

William A. Gahl, M.D., Ph.D., NHGRI clinical director and director of the NIH Undiagnosed Diseases Program adds:

“Vascular calcification often results from poor diet and lack of exercise. The calcium buildup in arteries of our patients, however, arises because the systems to inhibit it are not working in their cells. We hope that an understanding of this faulty mechanism will guide us in providing helpful treatments for these patients.”

The research was an international effort and included the NIH Office of Rare Disease Research; the NIH Clinical Center; St. John the Baptist Hospital, Turin, Italy; University of California, San Francisco; and Great Ormond Street Hospital-University College, London.

Sources: New England Journal of Medicine and The National Institutes of Health

Written By Sy Kraft, B.A.