title: A case of hereditary spherocytosis misdiagnosed as pyruvate kinase deficient hemolytic anemia.
abstract: BACKGROUND
  Hereditary spherocytosis (HS) and pyruvate kinase (PK) deficiency are the most common causes of congenital hemolytic anemia. We describe a case of HS with defective PK activity initially misdiagnosed as PK deficiency.
  
  
  METHODS
  Hematologic investigation, SDS-PAGE analysis of red cell membrane proteins and sequencing of the PKLR gene were performed.
  
  
  RESULTS
  The molecular characterization of the PKLR gene showed a heterozygous mutation 994G > A (Gly332Ser) associated with the promoter substitution -148C > T, whose role in the pathophysiology of PK deficiency is debated. Further investigations revealed spectrin deficiency; the family study demonstrated that the hemolysis was exclusively attributable to HS.
  
  
  CONCLUSIONS
  The present case pinpoints to the need for extensive family investigations to correctly diagnose chronic hemolytic anemia, in particular when molecular characterization does not fully explain the clinical phenotype.
authors.affiliation: Hematology and Transplantation Unit, Pathophysiology ofAnemia, Foundation IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, Italy.
authors.forename: Cristina
authors.initials: C
authors.lastname: Vercellati
authors.forename: Anna Paola
authors.initials: AP
authors.lastname: Marcello
authors.forename: Elisa
authors.initials: E
authors.lastname: Fermo
authors.forename: Wilma
authors.initials: W
authors.lastname: Barcellini
authors.forename: Alberto
authors.initials: A
authors.lastname: Zanella
authors.forename: Paola
authors.initials: P
authors.lastname: Bianchi
mesh_terms: D000293:Adolescent; D000746:Anemia, Hemolytic, Congenital Nonspherocytic / Q000175:diagnosis*; D003951:Diagnostic Errors; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008297:Male; D011770:Pyruvate Kinase / Q000172:deficiency; D015323:Pyruvate Metabolism, Inborn Errors / Q000175:diagnosis*; D013103:Spherocytosis, Hereditary / Q000175:diagnosis*
chemical_list: D011770:Pyruvate Kinase