Hereditary pyropoikilocytosis (HPP) is an
autosomal recessive
In genetics, dominance is the phenomenon of one variant (allele) of a gene on a chromosome masking or overriding the effect of a different variant of the same gene on the other copy of the chromosome. The first variant is termed dominant and t ...
form of
hemolytic anemia
Hemolytic anemia or haemolytic anaemia is a form of anemia due to hemolysis, the abnormal breakdown of red blood cells (RBCs), either in the blood vessels (intravascular hemolysis) or elsewhere in the human body (extravascular). This most commonly ...
characterized by an abnormal sensitivity of
red blood cell
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...
s to heat and erythrocyte morphology similar to that seen in thermal burns or from prolonged exposure of a healthy patient's blood sample to high ambient temperatures. Patients with HPP tend to experience severe
hemolysis
Hemolysis or haemolysis (), also known by several other names, is the rupturing (lysis) of red blood cells (erythrocytes) and the release of their contents (cytoplasm) into surrounding fluid (e.g. blood plasma). Hemolysis may occur in vivo o ...
and
anemia
Anemia or anaemia (British English) is a blood disorder in which the blood has a reduced ability to carry oxygen due to a lower than normal number of red blood cells, or a reduction in the amount of hemoglobin. When anemia comes on slowly, th ...
in infancy that gradually improves, evolving toward typical
elliptocytosis
Hereditary elliptocytosis, also known as ovalocytosis, is an inherited blood disorder in which an abnormally large number of the person's red blood cells are elliptical rather than the typical biconcave disc shape. Such morphologically distinctive ...
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 is a cytoskeletal protein that lines the intracellular side of the plasma membrane in eukaryotic cells. Spectrin forms pentagonal or hexagonal arrangements, forming a scaffold and playing an important role in maintenance of plasma membr ...
and with
spectrin deficiency. It was characterized in 1975. It is considered a severe form of
hereditary elliptocytosis
Hereditary elliptocytosis, also known as ovalocytosis, is an inherited blood disorder in which an abnormally large number of the person's red blood cells are elliptical rather than the typical biconcave disc shape. Such morphologically distinctive ...
.
Causes
Mutations of the alphaspectrin gene causes this disease.
HPP can be considered as a subset of hereditary elliptocytosis.
Diagnosis
Genetic testing for the presence of mutations in protein molecules is considered to be a confirmatory testing technique. It is important to know the risks regarding the transmission and dangers of HPP.
Treatment
Splenectomy
A splenectomy is the surgical procedure that partially or completely removes the spleen. The spleen is an important organ in regard to immunological function due to its ability to efficiently destroy encapsulated bacteria. Therefore, removal of ...
is a possible treatment
See also
*
Erythrocyte
Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...
*
Poikilocytosis
Poikilocytosis is variation in the shapes of red blood cells. Poikilocytes may be oval, teardrop-shaped, sickle-shaped or irregularly contracted.
Normal red blood cells are round, flattened disks that are thinner in the middle than at the edges. A ...
*
List of hematologic conditions
:''This is an incomplete list, which may never be able to satisfy certain standards for completion.''
There are many conditions of or affecting the human hematologic system—the biological system that includes plasma, platelets, leukocytes, an ...
References
External links
Red blood cell disorders
Autosomal recessive disorders
Cytoskeletal defects
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