Sarah Leigh Added comment: Comment on list classification: Rating changed from green to red, as the phenotypic features associated with RRM2B variants are metabolic renal disease / renal tubulopathy. RRM2B is green on Mitochondrial disorders (https://panelapp.genomicsengland.co.uk/panels/112/gene/RRM2B/) and Inborn errors of metabolism (https://panelapp.genomicsengland.co.uk/panels/467/gene/RRM2B/) panels.