title: Laboratory abnormalities in patients with myotonic dystrophy type 2.
abstract: BACKGROUND
  Myotonic dystrophy type 2 (DM2) is a recently discovered adult muscular dystrophy. Similar to DM1, this disease causes progressive debilitating weakness, clinical myotonia, and early cataracts and is thought to cause widespread physiologic dysfunction of multiple organ systems.
  
  
  OBJECTIVE
  To analyze and compile the laboratory abnormalities of patients with DM2.
  
  
  METHODS
  Baseline DM2 laboratory data were compiled representing 68 different types of laboratory tests and 1442 total studies.
  
  
  METHODS
  University medical center.
  
  
  METHODS
  Eighty-three adults with genetically confirmed or clinically probable DM2 were identified. Of these patients, 49 had documented baseline laboratory screening.
  
  
  METHODS
  The individual frequencies of abnormal laboratory values in the population with DM2 studied.
  
  
  RESULTS
  Of the 1442 studies, results for 359 (24.9%) were outside of their standard reference ranges. Of the 68 types of laboratory tests studied, 43 had values from 15 or more different patients with DM2. The relative frequency of an abnormally elevated laboratory value was greater than 50% in several tests, including the levels of creatine kinase, total cholesterol, lactate dehydrogenase, and alanine aminotransferase. In addition, serum levels of IgG were low in 75% of all patients with DM2 tested, and absolute lymphocyte counts were low in 54% of all patients with DM2 tested.
  
  
  CONCLUSIONS
  There is a high frequency of laboratory abnormalities in patients with DM2. These abnormalities provide insight into the widespread pathologic manifestations of DM2 and may form a basis for clinical monitoring and disease screening.
authors.affiliation: Neuromuscular Division, Department of Neurology, University of Rochester Medical Center, Rochester, NY 14642, USA. Chad_Heatwole@URMC.Rochester.edu
authors.forename: Chad
authors.initials: C
authors.lastname: Heatwole
authors.forename: Nicholas
authors.initials: N
authors.lastname: Johnson
authors.forename: Bradley
authors.initials: B
authors.lastname: Goldberg
authors.forename: William
authors.initials: W
authors.lastname: Martens
authors.forename: Richard
authors.initials: R
authors.lastname: Moxley
mesh_terms: D000046:Academic Medical Centers / Q000379:methods; D000328:Adult; D019411:Clinical Laboratory Techniques / Q000379:methods; D003955:Diagnostic Tests, Routine / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D020967:Myotonic Disorders / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics; D009223:Myotonic Dystrophy