Evaluation of Rare and Novel Genetic Variants as Possible Causes of Hereditary Hemolytic Anemia

Abstract

By Anna Ottlinger, Biology

Advisor: Daniel Buchholz

Presentation ID: PM_D20

Abstract: Hereditary hemolytic anemias (HHAs) due to hemoglobin, red blood cell (RBC) cytoskeleton and enzyme disorders are the most common genetic diseases. As the name implies, they are heritable conditions that result in RBCs prone to lyse, resulting in anemia. Genetic testing for these conditions is becoming more refined and more widely available. As new genetic variants are detected in individuals with HHA of unknown etiology, it is necessary to document changes in the corresponding proteins and correlate them with RBC characteristics and patient symptoms e.g., weakening of the cytoskeleton to create fragile RBC more prone to lysis. I tested RBC membrane samples from individuals with HHA and novel or rare genetic variants for protein anomalies (in quantity, size, etc.) that might correlate with the variants. Techniques used included standard protein electrophoresis with infrared imaging and protein capillary electrophoresis with immunodetection. Specifically, I evaluated the ratio of the cytoskeletal proteins actin and spectrin in the RBC membranes of an individual with a novel mutation in RAC2, a gene which codes for a RBC cytoskeleton modulating protein controlling actin polymerization and assembly. I also evaluated the protein ankyrin, which anchors the specialized RBC cytoskeleton to the cell membrane, in two patients with rare or novel variants in the ANK1 gene. The long-term goal of this work is to increase our understanding of the underlying mechanisms of HHAs and improve their diagnosis and treatment.