title: Case-control studies of novel hemoglobin anomalies as differential diagnosis in sleep apnea syndrome.
abstract: OBJECTIVE
  Pulse oximetry plays an essential role in the diagnosis of sleep apnea syndrome. We discovered two novel hemoglobin anomalies, Hb Bonn and Hb Venusberg, which initially resulted in avoidable sleep disorder examinations and therapeutic consequences due to their low oxygen saturation levels as measured by pulse oximetry.
  
  
  METHODS
  Hematological as well as clinical chemical diagnosis was carried out. Hemoglobin anomalies were detected through electrophoresis, chromatography, spectrophotometry, and pulse oximetry as well as hemoglobin gene sequencing.
  
  
  RESULTS
  Hb Bonn is a novel hemoglobin mutation of the proximal α1 globin with an additional absorption maximum of the oxyhemoglobin at 668 nm. This results in pulse oximetry measurements of false low oxygen saturation due to incorrect calculations at the pulse oximetry measuring point 660 m. Hb Venusberg is a novel oxygen-affine hemoglobin mutation of the β-globin which is electrophoretically silent. Clinical symptoms include intermittent low oxygen saturation levels, cyanosis of lips and nail beds, and limited physical resistance to stress.
  
  
  CONCLUSIONS
  Hemoglobin anomalies, such as Hb Bonn and Hb Venusberg, should be included in differential diagnosis as potential causes of low oxygen saturation especially in case of nonspecific or conflicting findings.
authors.affiliation: Department of Clinical Chemistry and Clinical Pharmacology, University of Bonn, Sigmund-Freud-Str. 25, 53127 Bonn, Germany. berndt.zur@ukb.uni-bonn.de
authors.forename: Berndt
authors.initials: B
authors.lastname: Zur
authors.forename: Michael
authors.initials: M
authors.lastname: Ludwig
authors.forename: Birgit
authors.initials: B
authors.lastname: Stoffel-Wagner
mesh_terms: D000328:Adult; D001797:Blood Protein Electrophoresis; D016022:Case-Control Studies; D002851:Chromatography, High Pressure Liquid; D003937:Diagnosis, Differential; D005260:Female; D006455:Hemoglobins, Abnormal / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010100:Oxygen / Q000097:blood; D017286:Polysomnography; D017422:Sequence Analysis, DNA; D020181:Sleep Apnea, Obstructive / Q000097:blood* / Q000175:diagnosis* / Q000235:genetics
chemical_list: D006455:Hemoglobins, Abnormal; C528769:hemoglobin Bonn; D010100:Oxygen