Pitfalls in the biological diagnosis of common hemoglobin disorders.
In West-European countries, hemoglobin disorders are no more rare diseases. Programs for diagnosis of heterozygous carriers have been established to prevent cases with major sickle cell disease or thalassemias. These studies have been done essentially by high performance liquid chromatography on cation-exchange columns and electrophoresis (mostly capillary electrophoresis). They have been done through systematic population studies or premarital diagnosis. We describe in this work the frequent or rare pitfalls encountered, which led to false negative or positive diagnosis both in the field of sickle cell disease and thalassemias. In the absence of a well identified hemoglobin disorder in the proband's family, it is a rule that the use of a single test is insufficient to identify formally HbS. The presence of HbS could also be masked by another hemoglobin abnormality. The sole measurement of HbA2 level is insufficient to characterize a thalassemic trait: this level needs always to be interpreted considering RBC parameters and iron metabolic status. In difficult cases, the definitive answer may require a family study and/or a molecular genetic characterization.
Inserm U955 équipe 2, Institut Mondor de recherche biomédicale, Créteil, France.
Henri
H
Wajcman
Service de génétique médicale, CHU de Nantes, France.
Kamran
K
Moradkhani
D002851:Chromatography, High Pressure Liquid; D004586:Electrophoresis; D006580:Genetic Carrier Screening; D005820:Genetic Testing; D006443:Hemoglobin A2 / Q000032:analysis; D006451:Hemoglobin, Sickle / Q000032:analysis; D006453:Hemoglobinopathies / Q000175:diagnosis* / Q000235:genetics; D006801:Humans
D006451:Hemoglobin, Sickle; D006443:Hemoglobin A2
HbS; chromatography; electrophoresis; neonatal diagnosis; pitfalls in diagnosis; premarital diagnosis; thalassemia