Background:Deficiency of Adenosine Aminase deficiency 2 is monogenic disease presenting with multisystem involvement of vasculitis,Stroke1,hematological manifestations. We hereby present a young child who presented with PRES initially and later diagnosed as DADA2.Only one case of DADA2 presenting as PRES is reported so far2.This case highlights the atypical presentation of DADA2.Objectives:A case report to highlight the rare presentation of DADA2 vasculits.Methods:8 year old developmentally normal male child,born out of consanguineous marriage presented with with fever,abdominal pain, seizures 1 year back.Ultrasound of abdomen revelaed mesenteric lymphadenitis and MRI Brain was suggestive of Meningoencephalitis.He was managed with antivirals and antibiotics then.6 months later,he had fever,skin rash,pain abdomen,status epilepticus,hypertension followed by gangrene of fingers and toes.APLA,ANA,ANCA workup was negative. Complete Hemogram was normal. CRP was 130mg/dl. CT Abdomen was normal and no evidence of aneurysms. Renal Doppler Ultrasound was normal.CT upper limb showed left radial and ulnar artery significant narrowing with patchy occlusion. MRI Brain showed bilateral fronto parietal,occipital,putamen,left insula and subcortical and cortical T2W FLAIR hyperintensity without diffusion restriction suggestive of PRES. He was diagnosed as Childhood Polyarteritis Nodosa and treated with cyclophosphamide. Genetic Analysis of ADA2(CECR1) gene mutation by Sanger Sequencing of exons 2 to 10 showed a known variant (rs202134424) in ADA2 gene.Figure 1.Gangrene of left 1-5th digits and right 4th and 5th digit resorptionFigure 2.T2W FLAIR image showing bilateral fronto parietal,occipital,putamen,left insula and subcortical and cortical hyperintensity without diffusion restriction suggestive of PRES.Results:He was started on Infliximab and is on follow up. No further events noted so far.Rehabilitation of left upper hand was done.Conclusion:DADA2 can present with varied CNS manifestations like infarct,hemorrhage,aneurysms and PRES.High index of suspicion and early recognition can help in maintaining vascular integrity.References:[1]Ganhão S, Loureiro G, Oliveira D, dos-Reis-Maia R, Aguiar F, Quental R et al. Two cases of ADA2 deficiency presenting as childhood polyarteritis nodosa: novel ADA2 variant, atypical CNS manifestations, and literature review. Clinical Rheumatology. 2020;39(12):3853-3860.[2]Sharma A, Naidu G, Sharma V, Jha S, Dhooria A, Dhir V et al. Deficiency of Adenosine Deaminase 2 in Adults and Children: Experience From India. Arthritis & Rheumatology. 2020;73(2):276-285.Disclosure of Interests:None declared