Hereditary Piropoiquilocitosis (Hereditary pyropoikilocytosis -HPP-) - Gen SPTA1.
Hereditary piropoiquilocitosis (HPP) is a disorder characterized by hemolytic anemia, microspherocytosis, poikilocytosis and an unusual thermal sensitivity of the red blood cells.
This process is due to mutations in the gene SPTA1, located on the long arm of chromosome 1 (1q21). This gene encodes the alpha chain of spectrin, which is in the erythrocyte membrane. This protein is the main constituent of the underlying network to the plasma membrane of erythrocytes cytoskeleton. It is associated with the band 4.1 and actin to form the superstructure of the cytoskeleton of the plasma membrane of erythrocytes.
Mutations in the gene associated with hereditary SPTA1 piropoiquilocitosis (HPP), leading to an excessively rigid and deformed cell. Instead of a flattened disk shape, these cells are spherical. An identified in SPTA1 gene mutation replaces the amino acid proline amino acid leucine at position 207 of alpha-spectrin chain (L207P), which results in a dysfunctional protein responsible for the weakness of the cytoskeleton of erythrocytes, which interferes with the ability of the cell to change shape when flowing through blood vessels.
This disease is inherited in an autosomal recessive pattern, that is, 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 hereditary piropoiquilocitosis (HPP), by complete PCR amplification of the exons of the gene SPTA1, 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).