MONDO_0014389 (polyglucosan body myopathy 1 with or without immunodeficiency) is a rare, genetic, glycogen storage disorder characterized by polyglucosan accumulation in various tissues, manifesting with progressive proximal muscle weakness in the lower limbs and rapidly progressive, usually dilated, cardiomyopathy. Hepatic involvement and growth retardation may be associated. Early-onset immunodeficiency and autoinflammation, presenting with recurrent bacterial infections, have also been reported. Also known as: PGBM1, polyglucosan body myopathy type 1, polyglucosan body myopathy, early-onset, with or without immunodeficiency.