Phosphoglycerate kinase deficiency: an adult myopathic form with a novel mutation.

The authors report a 36-year-old man with exertional myoglobinuria and muscle cramp without hemolytic anemia or CNS symptoms. They found a deficiency of phosphoglycerate kinase (PGK) activity in muscle and erythrocytes and a 4-base pair deletion in exon 6 of the PGK gene. This mutation may cause a frameshift, yielding an abnormal stop codon in exon 6 by which a truncated PGK protein was produced. This phenotype is caused by a novel mutation of the PGK gene.