To the Editor:
Deficiency of adenosine deaminase 2 (DADA2) causes a vasculopathy with autoinflammatory features associated with mutations in CECR11. The phenotype of DADA2 varies from only cutaneous lesions to full-blown systemic disease with central nervous system (CNS) involvement and aneurysms in visceral arteries that may overlap with the spectrum of polyarteritis nodosa (PAN)1,2,3.
The Chapel Hill Consensus Conference (CHCC) 2012 defines PAN as a necrotizing vasculitis of medium or small arteries without glomerulonephritis or vasculitis in arterioles, venules, or capillaries and not associated with antineutrophil cytoplasmic antibodies4. Now, with the discovery of DADA2, we know that monogenic disorders may cause a PAN-like vasculopathy. Thus, DADA2 should be classified under the group of “vasculitis with a probable cause” in CHCC 20124.
We herein present the characteristics of 6 DADA2 patients and their response to various therapies.
Three of our patients had been initially screened at the U.S. National Institutes of Health (NIH) because they had suggestive features for the CECR1 mutations. Subsequently, we screened 17 patients with suggestive features and identified 3 new cases. We have evaluated the course of these patients for a followup of median 8.5 years. All patients were Turkish and were followed in the departments of Rheumatology and Pediatric Rheumatology at Hacettepe University, Ankara, Turkey. Three (patients 2, 3, and 5) had been included in a previous paper2.
Peripheral blood samples for DNA extraction were obtained. Sanger sequencing was performed to sequence 10 exons of CECR1 in NIH (n = 3) and Hacettepe University (n = 3). Primer sequences are available in the Appendix. PCR products were directly sequenced using ABI Prism 3130 Automated Sequencer (Applied Biosystems).
We defined 6 DADA2 patients from 5 families. The characteristics and treatment of patients …
Address correspondence to Dr. S. Ozen, Department of Pediatrics, Division of Rheumatology, Hacettepe University Faculty of Medicine, Ankara 06100, Turkey. E-mail: sezaozen{at}hacettepe.edu.tr