<unk>  also known as McArdle's disease is caused by the deficiency of myophosphorylase. In 1951, Brian McArdle first described<unk> . It is an autosomal recessive disorder caused by mutation of the gene PYGM which is located on chromosome 11q13. Myophosphorylase is the isozyme of phosphorylase specific to muscles. Its deficiency leads to blockage of carbohydrate metabolic pathways causing accumulation of excess glycogen in the muscles. Muscles are unable to produce energy from glycogen and may lead to rhabdomyolysis.<unk>  commonly affects individuals in the 2nd-3rd decade of their life. There is insufficient evidence to recommend routine screening for<unk>  but carrier screening of at-risk relatives may be done. Different individuals present uniquely depending on the severity of enzyme deficiency. Some adults can develop progressive proximal muscle weakness or fixed motor weakness. A "Second-wind phenomenon" can be seen in patients suffering from<unk> . Burgundy-colored urine can be seen after an intense session of exercise due to rhabdomyolysis. On physical examination, persistent weakness and muscle wasting may be seen as the patient ages. Laboratory findings may show elevated levels of creatine kinase levels in almost 90% of patients suffering from<unk> . Forearm exercise test and electromyography are used to diagnose GSD type V. Treatment includes dietary modification and mild to moderate aerobic exercises like walking or bicycling.
Glycogen storage disease type V
Glycogen storage disease type I CT
Glycogen storage disease type III
Glycogen storage disease type I
Glycogen storage disease type IV
Glycogen storage disease type II
Glycogen storage disease type XI
Essential fructosuria