McArdle’s Disease have first described by Doctor Brian McArdle in year 1951. This disease another name is Glycogen storage disease type V also. In this disease myophosphorylase enzyme activity deficiency is available. For this reason, glucose can not released from the muscles in to blood. This disease is also a rare disease that may seen in 1 of 150.000 persons.
This disease is an autosomal recessive disorder. The defective gene myophosphorylase (PYGM) have localised on chromosome 11. Because autosomal recessive inheritance, this disease is more common in consanguineous marriage. One defective gene may not cause to this disease. This patients may only asymptomatic carriers. If the both PYGM gene is defective, the patient will develop this disease.
Exercise intolerance may seen as the first finding. After an activity, unknown progressive proximal weakness, muscle cramps and fatigue will seen. This finding may seen in first decade, but this disease will mostly diagnosed in 30-40 years of age. Serum creatine kinase level will elevated in these patients also after strenuous activity and then myoglobinuria may start. Blood creatine kinase level will exceed 1,000 IU/L. Blood lactate concentrations will increase and lactic acidosis may develop. Long term myoglobinuria attacks will cause to kidney damage in untreated persons.
There are no cure for this disease. Avoid strenuous activity like aerobic and long term run needed sport like football, basketball and long way tracking. Only slow tempo walking will beneficiary also. Before any exercise, drinks or meals that contains simple carbohydrates (glycogen) will beneficial. Prenatal diagnosis for pregnancies at increased risk may planned also. Light sports are beneficial for this patient’s.With it, if any symptom starts, that can be taken under control with some techniques also. Vitamin B6 supplements are helpful for treatment also. Angiotensin converting enzyme derived drugs are beneficial too.
With supportive treatment this disease will not affect the life expectancy. This disease will mostly affect the life comfort with exercise and will decrease exercise durability.