hereditary elliptocytosis

Hereditary elliptocytosis (HE) refers to a group of inherited blood conditions where the red blood cells are abnormally shaped, assuming an elliptical shape rather than the typical round or biconcave disc shape [2]. This condition is characterized by the presence of elongated, elliptically-shaped red blood cells on the peripheral blood smear [3].

The symptoms associated with HE can range from absent to life-threatening hemolytic anemia, depending on the severity of the condition and the individual's genetic makeup [4]. In some cases, the hemolysis may be slight or absent, with little or no anemia except in patients who are homozygous (hereditary pyropoikilocytosis) [5].

HE is a rare autosomal dominant disorder caused by mutations in spectrin, protein 4.1, or glycophorin C, which weaken the skeletal protein interactions and increase red blood cell mechanical fragility [7]. Heterozygotes usually have mild or no symptoms, while homozygous individuals may experience more severe manifestations.

The condition is inherited in an autosomal dominant pattern, meaning that a single copy of the mutated gene is sufficient to cause the disorder. The osmotic fragility is normal in HE patients, and the majority of red blood cells have an elliptical shape [12].

In some cases, HE can be associated with hemolytic anemia, which may manifest differently in different individuals. For example, a family study found that four children from two sibships had hemolytic anemia associated with hereditary elliptocytosis but had different manifestations [13].

Hereditary elliptocytosis, also known as hereditary ovalocytosis, is a rare genetic disorder characterized by abnormally shaped red blood cells (RBCs). The diagnostic tests for this condition are crucial in confirming the diagnosis and ruling out other possible causes of anemia. Here are some of the key diagnostic tests used to diagnose hereditary elliptocytosis:

• Peripheral Blood Smear: This is a simple test where a sample of blood is examined under a microscope to look for abnormal RBC shapes, such as elongated or oval-shaped cells.
• Red Blood Cell (RBC) Fragility Assay: This test measures the fragility of RBCs by exposing them to varying concentrations of salt solutions. In hereditary elliptocytosis, RBCs are more fragile than normal.
• RBC Autohemolysis Assay: This test measures the rate at which RBCs break down (autohemolysis) in a sample of blood. In hereditary elliptocytosis, RBC autohemolysis is often increased.
• Direct Antiglobulin (Coombs) Test: This test detects the presence of antibodies against RBCs, which can be present in hereditary elliptocytosis.
• Genetic Testing for Membranopathies: This test involves analyzing DNA to identify genetic mutations that cause membrane-related disorders, including hereditary elliptocytosis.

According to [4], the diagnosis of hereditary elliptocytosis and its more severe form, hereditary pyropoikilocytosis (HPP), relies on identifying abnormal RBC morphology on peripheral blood smear (elliptocytes, poikilocytosis and fragmented RBCs), and identifying characteristic membrane biomechanical properties using osmotic gradient ektacytometry.

In addition to these tests, a family history of the condition can also be an important factor in diagnosing hereditary elliptocytosis. A diagnosis is usually made by coupling a family history of the condition with an appropriate clinical presentation and confirmation on a blood smear [7, 8].

It's worth noting that a high percentage (at least 25%) of abnormally shaped RBCs in the specimen is required to confirm the diagnosis of hereditary elliptocytosis [8].

Hereditary elliptocytosis, also known as ovalocytosis, is an inherited blood disorder characterized by abnormally shaped red blood cells. While there is no specific treatment for the condition, certain medications and interventions may be used to manage symptoms and complications.

Folic Acid Supplements

A diet rich in folic acid or folic acid supplementation is recommended to avoid consequences of folate deficiency in a hemolytic state [1]. This is particularly important for patients with clinically significant hemolytic anemia.

Iron Supplements

Iron supplements may be prescribed to improve anemia symptoms, as the condition can lead to iron deficiency due to increased red blood cell turnover [9].

Blood Transfusions

In severe cases of hereditary elliptocytosis, blood transfusions may be necessary to replace damaged red blood cells and maintain adequate oxygen delivery to tissues [8].

Splenectomy

Splenectomy, or surgical removal of the spleen, is considered in patients with symptomatic hemolysis or complications such as biliary colic or persistent aplastic crisis [2]. However, it's essential to note that splenectomy may not be effective in all cases and can have potential risks.

Other Interventions

In some cases, other interventions like red cell transfusion and supportive care may be necessary to manage symptoms and complications [4].

It is crucial for patients with hereditary elliptocytosis to consult with a healthcare provider for complete information about their health, medical questions, and treatment options [12].

Hereditary elliptocytosis (HE) can be challenging to diagnose due to its heterogeneous nature and overlapping clinical features with other conditions. The differential diagnosis for HE includes:

• Southeast Asian ovalocytosis (SAO): This condition has a similar morphological appearance on peripheral blood smears but distinct molecular pathogenesis and physiology.
• Hereditary spherocytosis: Although characterized by spherical-shaped red blood cells, HS can be distinguished from HE based on the presence of elliptical RBCs in the latter.
• Iron deficiency anemia: Mild hemolytic anemia in HE may mimic iron deficiency anemia, but the two conditions have distinct underlying causes and clinical presentations.
• Thalassemias: Certain types of thalassemia can present with mild hemolytic anemia and elliptical RBCs, making them a differential diagnosis for HE.
• Megaloblastic anemias: These conditions can also cause mild hemolytic anemia and changes in red blood cell morphology, including elliptocytosis.
• Myelofibrosis, myelophthisic anemia, myelodysplastic syndrome, and pyruvate kinase deficiency are other acquired or inherited conditions that can be associated with elliptocytosis and poikilocytosis.

To establish a diagnosis of HE, it is essential to consider the patient's family history, clinical presentation, and laboratory findings, including the presence of at least 25% abnormally shaped RBCs on peripheral blood smears [11][15].