S4982 A Novel Association of Danon Disease and Crohn’s Disease

Introduction: Danon disease is an X-linked dominant mutation of the LAMP2 gene manifesting with progressive hypertrophic cardiomyopathy, progressive proximal muscle weakness, and cognitive impairment. Herein, we describe the first reported association of Crohn's disease (CD) and Danon disease. Case Description/Methods: A 19-year-old man with a history of infiltrative hypertrophic cardiomyopathy secondary to Danon disease presented with an exacerbation of intermittent chronic diarrhea of 2 years’ duration. The patient had increasing loose stools 1 month after an elective orthoptic cardiac transplant for Danon disease. His symptoms were stress-induced with occasional hematochezia but there was no tenesmus or urgency. He reported pain in the upper gluteal fold close to the coccyx when straining. Current medications included mycophenolate mofetil and tacrolimus. His physical exam was normal while a stool culture, ova & parasites, cytomegalovirus (CMV) polymerase chain reaction and a tacrolimus level were unremarkable. To exclude post-transplant CMV colitis, a colonoscopy was performed which demonstrated a normal ileum but cobblestoning of the mucosa throughout the colon suggestive of CD. Biopsies of the transverse and descending colon confirmed severe chronic active colitis with ulceration and immunohistochemical staining negative for CMV infection. The patient was started on oral prednisone and sulfasalazine with subsequent symptomatic relief. Unfortunately, the patient later developed recurrent CD flares. Several pelvic magnetic resonance imaging following the initial colonoscopy demonstrated chronic perianal fistula over the next 2 years with treatment failure on sulfasalazine, vedolizumab, adalimumab, and infliximab. Ustekinumab was effective in inducing remission of his CD. The fistula was managed with seton placement and antibiotics. Discussion: We described a new diagnosis of colonic and perianal fistulising CD in a patient with Danon disease. Interestingly, the patient demonstrated active colonic disease post-cardiac transplant while on immunosuppressive mycophenolate mofetil and tacrolimus. Infectious causes should be excluded in a patient with Danon disease presenting with diarrhea, but the possibility of inflammatory bowel disease should also be considered.