Elliptocytosis type 3 (elliptocytosis 3 -EL3-) - Gen SPTB.

Elliptocytosis 3 (EL3) is a genetically heterogeneous hematologic autosomal dominant disease. It is characterized by hemolytic anemia and a varying elliptical or oval erythrocytes.

This process is due to mutations in the gene SPTB, located on the long arm of chromosome 14 (14q23-q24.2). This gene encodes a member of the gene family of spectrin. The spectrins proteins with ankyrin, play a role in the organization and stability of the cell membrane. The protein encoded by this gene plays a role in the stability of erythrocyte membranes. It is associated with the band 4.1 and actin to form the superstructure of the cytoskeleton of the plasma membrane of erythrocytes. Red blood cells have to be flexible to move from the arteries to the capillaries. This protein allows the cell to change shape as it passes through the narrow capillaries.

Mutations in the gene SPTB spectrin alter the synthesis or stability, leading to an excessively rigid and deformed cell. Instead of a flattened disk shape, these cells are spherical. Dysfunctional proteins interfere with the ability of the cell to change shape when passing through blood vessels.

This disease is inherited as an autosomal dominant, which means that a copy of the altered gene in each cell is sufficient for the disease to be expressed. In most cases, an affected person has a parent with the disease. In rare cases, the disease is inherited in an autosomal recessive pattern, which means that both copies of the gene in every cell must have mutations for alteration is expressed. The parents of an individual with an autosomal recessive disease have a copy of the mutated gene, but usually show no signs and symptoms of the disease.

Tests in IVAMI: in IVAMI perform detection of mutations associated with elliptocytosis 3 by the complete PCR amplification of the exons of the gene SPTB, and subsequent sequencing.

Samples recommended: EDTA blood collected for separation of blood leukocytes, or impregnated sample card with dried blood (IVAMI may mail the card to deposit the blood sample).