Recent Concepts in Lab Diagnosis of Inherited Red Blood Cell Membrane Disorders

Abstract

Hereditary red cell membrane disorders occur due to mutation in genes responsible for coding the membrane proteins, cytoskeletal protein, and transmembrane transporter or channel resulting in decrease in the permeability and deformability and premature removal of RBC from the blood stream. These rare disorders show marked clinical and laboratory heterogeneity. Diagnosis is often challenging despite the availability of many laboratory tests. Hereditary red blood cell membrane disorders present as hemolytic anemias occurring due to defective structural proteins and anomalous cations permeability of RBC membrane. Majority of patients present with characteristic red cell morphology and clinical feature which along with the first line of diagnostic tests helps in making an appropriate diagnosis. Multiple laboratory indicators have evolved that will allow for accurate diagnosis of the disease. A combination of 2 screening tests can be used and molecular testing should be done when all screening tests are negative. Tests like Osmotic fragility, Flow cytometry, Ektacytometry, RBC membrane protein electrophoresis and genomic analysis are used in combination with family history, red cell morphological examination and red cell indices for the diagnosis of various red cell membrane disorders.