title: Muscle phosphoglycerate mutase deficiency revisited.
abstract: BACKGROUND
  Phosphoglycerate mutase (PGAM) deficiency (glycogen storage disease type X) has been reported in 12 patients of whom 9 were African American.
  
  
  OBJECTIVE
  To describe 2 patients, 1 of Pakistani and 1 of Italian ethnic origin, with typical clinical and biochemical changes of glycogen storage disease type X and novel mutations in the gene encoding the muscle subunit of PGAM (PGAM2).
  
  
  METHODS
  Clinical, pathological, biochemical, and molecular analyses.
  
  
  METHODS
  Tertiary care university hospitals and academic institutions. Patients A 37-year-old Danish man of Pakistani origin who had exercise-related cramps and myoglobinuria and a 65-year-old Italian man who had exercise intolerance and myalgia but no pigmenturia and had undergone long-term statin therapy.
  
  
  METHODS
  Clinical course and biochemical and molecular features.
  
  
  RESULTS
  Biochemical evidence showed severe isolated PGAM deficiency, and molecular studies revealed 2 novel homozygous mutations, a nonsense mutation and a single nucleotide deletion. Pathological studies of muscle showed mild glycogen accumulation but prominent tubular aggregates in both patients.
  
  
  CONCLUSIONS
  We found that glycogen storage disease type X is not confined to the African American population, is often associated with sarcoplasmic reticulum (SR) proliferation, and is genetically heterogeneous.
authors.affiliation: Department of Neurology, Columbia University Medical Center, New York, New York, USA.
authors.forename: Ali
authors.initials: A
authors.lastname: Naini
authors.forename: Antonio
authors.initials: A
authors.lastname: Toscano
authors.forename: Olimpia
authors.initials: O
authors.lastname: Musumeci
authors.forename: John
authors.initials: J
authors.lastname: Vissing
authors.forename: Hasan O
authors.initials: HO
authors.lastname: Akman
authors.forename: Salvatore
authors.initials: S
authors.lastname: DiMauro
mesh_terms: D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000097:blood; D006008:Glycogen Storage Disease / Q000235:genetics* / Q000378:metabolism* / Q000503:physiopathology; D006801:Humans; D007558:Italy; D008297:Male; D010154:Pakistan; D010736:Phosphoglycerate Mutase / Q000172:deficiency* / Q000235:genetics
chemical_list: D003402:Creatine Kinase; D010736:Phosphoglycerate Mutase