glycogen storage disease type-VII (Tarui type glycogen storage disease)

Genetics: - autosomal recessive - associated with defects in PFKM gene Clinical manifestations: - exercise intolerance with associated nausea & vomiting - pain & stiffness on exertion - short bursts of intense activity are particularly difficult - severe muscle cramps & myoglobinuria develop after vigorous exercise - most patients obtain a 'second wind' when the onset of exercise is followed by a brief rest period - in time patients adjust their activity level & are well compensated Laboratory: - normal response of plasma glucose to IM glucagon - myoglobinuria after vigorous exercise

Properties

DEFICIENT-PROTEIN: phosphofructokinase COMPARTMENT: cytoplasm MOTIF: active site

References

Clinical Diagnosis & Management by Laboratory Methods, J.B. Henry (ed), W.B. Saunders Co., Philadelphia, PA. 1991, pg 185