DCHS1 and mitral valve prolapse: ,2,3 There are however only a few non-syndromic genes known to cause Mendelian forms of VHD including notch receptor 1 (NOTCH1) associated with developmental valve anomalies and severe valve calcification,4 filamin A (FLNA) associated with myxomatous valvular dystrophy,5 and dachsous cadherin-related 1 (DCHS1) associated with mitral valve prolapse.6