Gain-of-Function MN1 Truncation Variants Cause a Recognizable Syndrome with Craniofacial and Brain Abnormalities

MN1 was originally identified as a tumor-suppressor gene. Knockout mouse studies have suggested that Mn1 is associated with craniofacial development. However, no MN1-related phenotypes have been established in humans. Here, we report on three individuals who have de novo MN1 variants that lead to a protein lacking the carboxyl (C) terminus and who presented with severe developmental delay, craniofacial abnormalities with specific facial...