Mc Ardles disease is due to deficiency of

Glycogen storage diseases TYPE NAME DEFICIENT ENZYME CLINICAL FEATURES Type I von Gierke's disease Glucose-6-phosphatase Fasting hypoglycemia; hepatomegaly,thrombocyte dysfunction. Type II Pompe's disease Lysosomal maltase Accumulation of glycogen in lysosomes of liver, hea and muscle; death before 2 years Type III Limit dextrinosis (Cori's disease) Debranching enzyme Highly branched dextrin accumulates; Fasting hypoglycemia; hepatomegaly Type IV Amylopectinosis (Anderson's disease) Branching enzyme Glycogen with few branches; hepatosplenomegaly; mild- -hypoglycemia; death by age of 5 Type V McArdle's disease Muscle phosphorylase Excercise intolerance; accumulation of glycogen in muscles Type VI Her's disease Liver phosphorylase Mild hypoglycemia; hepatomegaly; better prognosis than other types REF: DM VASUDEVAN TEXTBOOK OF BIOCHEMISTRY,EIGHTH EDITION,PG.NO.,144.