The diagnosis of hemoglobin variants that are not any of the better-known forms of thalassemia, sickle cell, HbC, HbD, or HbE anomalies is often challenging and requires detailed knowledge of the difference in symptoms and analysis. Experience in laboratory medicine plays an important role as the range of variants is extensive and lack of expertise can result in a wrong diagnosis.
Hemoglobin variants with low oxygen affinity may present cyanosis and low oxygen saturation levels, whereas variants with increased oxygen affinity show polyglobulia and concomitant complications. Differential diagnosis of methemoglobin variants requires careful assessment, which can be problematic especially in pediatric medicine.
Other variants, due to their instability, can cause more or less distinct hemolysis or thalassemia syndromes depicting serious disease patterns. Clear distinction is not always possible as several symptoms are often present. Many variants are autosomal dominant inherited. The most common and originally endemic hemoglobin disorders thalassemia and sickle cell disease have long since spread to Central Europe through migration where they play an increasing role in clinical practice.
Rare hemoglobin anomalies represent a diagnostic challenge for the treating and diagnosing physician, and the full range of symptoms is sometimes underestimated Table 1. Medical laboratories perform hemoglobin chromatography or hemoglobin electrophoresis as standard diagnostic tools.
In many cases, however, this is not enough. Further diagnostics should be made available to specialists in order to avoid misinterpretations. Laboratory medicine must play a key role in this context. Hemoglobinopathies are divided into thalassemia and structural abnormalities of hemoglobin. Thalassemia is characterized by an imbalance of globin synthesis. Structural abnormalities of hemoglobin cause the formation of abnormal hemoglobin, the most famous being sickle cell hemoglobin.
