title: Phosphoglycerate mutase deficiency with tubular aggregates in a patient from Panama.
abstract: BACKGROUND
  Phosphoglycerate mutase deficiency (PGAM) is a rare metabolic myopathy that results in terminal block in glycogenolysis. Clinically, patients with PGAM deficiency are asymptomatic, except when they engage in brief, strenuous efforts, which may trigger myalgias, cramps, muscle necrosis, and myoglobinuria. An unusual pathologic feature of PGAM deficiency is the association with tubular aggregates.
  
  
  METHODS
  We report an African-American patient from Panama with partial deficiency of PGAM who presented with asymptomatic elevation of creatine kinase levels and tubular aggregates on muscle biopsy.
  
  
  RESULTS
  Muscle biopsies showed subsarcolemmal and sarcolemmal tubular aggregates in type 2 fibers. Muscle PGAM enzymatic activity was decreased and gene sequencing revealed a heterozygous mutation in codon 78 of exon 1 of the PGAM2 gene, which is located on the short arm of chromosome 7.
  
  
  CONCLUSIONS
  PGAM deficiency has been reported in 14 patients, 9 of whom were of African-American ethnicity, and in 5 (36%) tubular aggregates were seen on muscle biopsy. Contrary to previously reported cases, our patient was initially asymptomatic. This further expands the PGAM deficiency phenotype.
authors.affiliation: Department of Neurology University of Massachusetts Medical Center, 55 Lake Avenue North S5-751, Worcester, Massachusetts 01605, USA. johnnysalameh@hotmail.com
authors.forename: Johnny
authors.initials: J
authors.lastname: Salameh
authors.forename: Namita
authors.initials: N
authors.lastname: Goyal
authors.forename: Rabia
authors.initials: R
authors.lastname: Choudry
authors.forename: Sandra
authors.initials: S
authors.lastname: Camelo-Piragua
authors.forename: Peter Siao Tick
authors.initials: PS
authors.lastname: Chong
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D009120:Muscle Cramp / Q000201:enzymology / Q000235:genetics / Q000473:pathology*; D018908:Muscle Weakness / Q000201:enzymology / Q000235:genetics / Q000473:pathology*; D018482:Muscle, Skeletal / Q000201:enzymology / Q000473:pathology*; D010736:Phosphoglycerate Mutase / Q000172:deficiency* / Q000235:genetics / Q000378:metabolism
chemical_list: D010736:Phosphoglycerate Mutase