Hereditary pyropoikilocytosis (HPP) is an autosomal recessive form of hemolytic anemia

Hemolytic anemia

Hemolytic anemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells , either in the blood vessels or elsewhere in the human body . It has numerous possible causes, ranging from relatively harmless to life-threatening...

 characterized by an abnormal sensitivity of red blood cell

Red blood cell

Red blood cells are the most common type of blood cell and the vertebrate organism's principal means of delivering oxygen to the body tissues via the blood flow through the circulatory system...

s to heat and erythrocyte morphology similar to that seen in thermal burns. Patients with HPP tend to experience severe haemolysis and anaemia in infancy that gradually improves, evolving toward typical elliptocytosis later in life. However, the hemolysis can lead to rapid sequestration and destruction of red cells. Splenectomy is curative when this occurs.

HPP has been associated with a defect of the erythrocyte membrane protein spectrin

Spectrin

Spectrin is a cytoskeletal protein that lines the intracellular side of the plasma membrane of many cell types in pentagonal or hexagonal arrangements, forming a scaffolding and playing an important role in maintenance of plasma membrane integrity and cytoskeletal structure...

 and with spectrin deficiency.

It was characterized in 1975.

It is considered a severe form of hereditary elliptocytosis

Hereditary elliptocytosis

Hereditary elliptocytosis, also known as ovalocytosis, is an inherited blood disorder in which an abnormally large number of the sufferer's erythrocytes are elliptical rather than the typical biconcave disc shape. It is one of many red-cell membrane defects. In its severe forms, this disorder...

.