Hereditary Elliptocytosis

What happens in hereditary elliptocytosis

Red blood cells must squeeze through tiny capillaries and the spleen. Their flexibility depends on a mesh of proteins under the cell membrane, mainly spectrin, protein 4.1 and band 3. In elliptocytosis, faulty versions of these proteins weaken the mesh. As cells circulate, they become permanently stretched into ovals. In mild forms they still work normally. In severe forms the cells break apart easily and are removed by the spleen, causing hemolysis.

Types

Mild HE is usually inherited from one parent in an autosomal dominant pattern. Severe forms usually require two altered genes.

Symptoms

Most people have no symptoms. When hemolysis is significant:

• tiredness and shortness of breath on exertion
• pale skin
• jaundice, yellowing of the skin and eyes
• an enlarged spleen (splenomegaly)
• gallstones from excess bilirubin
• dark urine during flare-ups

Hemolysis can worsen temporarily during infections, pregnancy or vitamin deficiencies. Parvovirus B19 can cause an aplastic crisis, a sudden drop in red cell production.

Diagnosis

• Blood film: the key finding is many elliptocytes (often more than 25% of red cells, up to 100%).
• Full blood count: hemoglobin, red cell indices and reticulocyte count (raised in hemolysis).
• Signs of hemolysis: raised bilirubin and LDH, low haptoglobin.
• Family studies: parents and siblings may show elliptocytes.
• Specialized tests: eosin-5-maleimide binding, ektacytometry or genetic testing for severe or unclear cases.

Other causes of elliptocytes, such as iron deficiency, thalassemia, myelofibrosis and megaloblastic anemia, must be excluded. Elliptocytosis is related to, but distinct from, hereditary spherocytosis.

Treatment

• Mild HE: no treatment needed.
• Folic acid supplements for people with ongoing hemolysis, because red cell production uses extra folate.
• Blood transfusion for severe anemia, aplastic crises or in infants with severe forms.
• Splenectomy: removing the spleen reduces red cell destruction in severe hemolytic forms such as HPP. It is usually delayed until after age 5 to 6 and requires vaccinations (pneumococcal, meningococcal, Hib) and sometimes preventive antibiotics, due to infection risk.
• Cholecystectomy for symptomatic gallstones.
• Phototherapy for newborn jaundice.

Outlook

Most people with hereditary elliptocytosis live completely normal lives. People with severe forms usually do well with treatment, including splenectomy where needed. Genetic counseling helps families understand inheritance.

Frequently asked questions

What is hereditary elliptocytosis?

It is an inherited condition in which red blood cells are oval instead of round, due to faulty membrane proteins. Most people have no symptoms, but some have hemolytic anemia with tiredness, jaundice, an enlarged spleen and gallstones.

Is hereditary elliptocytosis serious?

Usually not. Most people have a mild form with no anemia and need no treatment. A small number have severe forms, such as hereditary pyropoikilocytosis, that cause significant anemia and need transfusions or removal of the spleen.

How is elliptocytosis inherited?

Most mild cases are inherited in an autosomal dominant way, so each child of an affected parent has a 50% chance of inheriting it. Severe forms usually occur when a child inherits altered genes from both parents.

What is the difference between elliptocytosis and spherocytosis?

Both are inherited red cell membrane disorders. In elliptocytosis, cells become oval; most people have no symptoms. In spherocytosis, cells become small and round, and hemolytic anemia is more common. Both can cause jaundice, an enlarged spleen and gallstones.