While it seems obvious that GBE1 deficiency is the cause in APBD, no changes in GBE1 and GYS1 levels or activities could be detected in LD (DePaoli-Roach et al, 2010; Sullivan et al, 2019; Tagliabracci et al, 2008; Tagliabracci et al, 2007; Tiberia et al, 2012; Valles-Ortega et al, 2011), even though GYS1 and PTG have been proposed as malin targets (Vilchez et al, 2007; Worby et al, 2008). This evidence concerns the gene NHLRC1 and adult polyglucosan body disease.