Biochemical and molecular genetic identification of patients with phosphoglycerate mutase deficiency

Phosphoglycerate mutase (PGAM) deficiency is an autosomal recessive glycogenosis (type X) characterised by exercise induced cramps, myalgia, and myoglobinuria. Myohistological features are glycogen deposition and tubular aggregates. Biochemically there is low muscle PGAM activity (most patients below 10%) but few manifesting heterozygotes with 50% activity are reported. Molecular genetic investigations have revealed 4 mutations among 13 patients, so far. A nonsense mutation W78X is frequent in patients of African origin. We performed biochemical and molecular genetic investigation (sequencing of the coding regio…