<prompt> Enzyme deficiency in McArdle syndromeMuscle phosphorylaseLiver phosphorylaseLiver debranching enzymeGlycogen synthase  <response>: Glycogen storage disorderTypeNameEnzyme DeficiencyClinical FeaturesType VMyophosphorylase deficiency,McArdle syndromeMuscle phosphorylasePoor exercise tolerance; muscle glycogen abnormally high2.5-4; blood lactate very low after exerciseRef: Harper;s Biochemistry; 30th edition; Table 18-2; Chapter 18; Metabolism of Glycogen 