SUMOylation is a type of protein modification occurring in the cell. It includes the attachment of Small Ubiquitin-like Modifier (SUMO) to large sets of proteins to regulate their function. Abnormalities in protein SUMOylation are linked with various disease states, however, knowledge of the specific roles of the SUMOylation machinery in human disease is limited. In this study, we identify for the first time that the absence of SUMO protease 7 (SENP7) results in a rare syndrome associated with fatal arthrogryposis multiplex congenita, early respiratory failure, and neutropenia. This was established through genetic sequencing of infants from a large consanguineous family who passed away from an unknown disorder. (By Dr. Karin Weiss, https://jmg.bmj.com/content/early/2023/07/17/jmg-2023-109267 )