Introduction: Mitral valve prolapse (MVP) has a high population prevalence 2-4% with an arrhythmogenic subtype presenting with premature ventricular complexes (PVC) ventricular tachycardia (VT) and sudden death. There is a continued search for markers of MVP to help risk stratify patients. Hypothesis: Arrhythmogenic MVP shares genetic etiology with Mendelian causes of arrhythmia and cardiomyopathy Methods: Consecutive adult patients with arrhythmogenic MVP patients prospectively evaluated Results: A total of 33 cases (age 55±15 years, female 51.5%) presented with history of hypertension (33%), diabetes (3%), coronary disease (12%), atrial fibrillation (45%), bileaflet MVP (58%) and syncope (18%). ECG findings include inverted T-waves in inferior leads in 6%, pleomorphic PVC in 6%, Ventricular couplets in 51.5%, non-sustained VT in 73% and sustained VT in 33%; High PVC burden was seen in 55% of cases with burden 15±14%. Echocardiography noted LV ejection fraction of 55±8%, mitral regurgitations in 70% (severe 18%, moderate 27%, mild 24%), mitral annular disjunction in 39%, and Pickelhaube sign in 9% of cases. Cardiac magnetic resonance showed LVESV 113±119mm, LVEDV 117±70mm, and late Gadolinium enhancement in 48% with highest prevalence in basal inferolateral segment. PET-CT performed in 17 cases and showed fluorodeoxyglucose uptake in 24% cases, mostly in basal inferolateral segment as well. Genetic testing was performed in 23 cases and reported a putative pathogenic variant in 21.7%: FLNC (Exemplar case, Figure 1 ) cause of dilated cardiomyopathy, TBX5 cause of Holt-Oram syndrome, DSP cause of arrhythmogenic cardiomyopathy , TTN causes of dilated cardiomyopathy, MTO1 cause of mitochondrial hypertrophic cardiomyopathy. Conclusion: Full evaluation of arrhythmogenic MVP with multimodality imaging and genetic testing reveals high burden of fibrosis, inflammation, and candidate pathogenic variants.