Alternative titles and symbols : Muscle phosphorylase kinase deficiency; Gsd ixd; Muscle glycogenosis, X-linked;
Description : Glycogen storage disease type IXd is an X-linked recessive, relatively mild metabolic
disorder characterized by variable exercise-induced muscle weakness or stiffness.
Most patients have adult-onset of symptoms, and some can remain asymptomatic even
in late adulthood. The phenotype is usually only apparent with intense exercise (summary
by Preisler et al., 2012).;
Inheritance : X-linked recessive;
Molecular basis : Caused by mutation in the muscle-specific phosphorylase kinase subunit A1 gene (PHKA1,
311870.0001);