What are the other Names for this Condition? (Also known as/Synonyms)
- Hereditary Ovalocytosis
- Melanesian Elliptocytosis
- Southeast Asian Ovalocytosis (SAO)
What is Hereditary Elliptocytosis? (Definition/Background Information)
- Hereditary Elliptocytosis (HE) is a rare congenital disorder characterized by oval-shaped red blood cells. It is also known as Hereditary Ovalocytosis
- The disorder is caused by gene deletion on chromosome 17. A positive family history is a key risk factor for Hereditary Elliptocytosis
- Many adults with Hereditary Elliptocytosis tend to be asymptomatic. Children may have signs and symptoms including anemia and jaundice
- A healthcare professional will use diagnostic tests, such as a physical exam, previous medical history, complete blood count, and a blood smear study, in order to diagnose the condition
- Upon diagnosis, the treatment options may include blood transfusion and splenectomy (spleen removal), if necessary, to control the signs and symptoms. The severity of the condition varies from one individual to another. Some individuals with mild signs and symptoms often may not require any treatment
- The prognosis of Hereditary Elliptocytosis depends on the severity of the signs and symptoms and the response to treatment. Some individuals may develop complications, such as gallstone formation and kidney impairment, which can lead to a poor prognosis
There are 3 major types of Hereditary Elliptocytosis, which include:
- Common Hereditary Elliptocytosis: It is the most common type of Hereditary Elliptocytosis. The signs and symptoms vary a lot; about 5-10% of the individuals have severe signs and symptoms
- Spherocytic Elliptocytosis: It generally occurs in individuals of European ethnic background
- Southeast Asian Ovalocytosis: This type is more common among the Southeast Asian populations. It is also known as Stomatocytic Elliptocytosis. The presentations are often mild. Also, because of the unique shape of RBCs, there is a natural resistance against malarial parasitic infection
Who gets Hereditary Elliptocytosis? (Age and Sex Distribution)
- Hereditary Elliptocytosis is a congenital disorder. In children with severe signs and symptoms, the condition is often seen at birth and infancy. Individuals with milder signs and symptoms may present the condition during adulthood
- It can affect both males and females and no gender preference is observed
- Hereditary Elliptocytosis is common among individuals of Southeast Asian descent. Individuals of all races and ethnic groups can be at risk. However, some forms of HE are more common among certain populations (such as among Europeans or Asian populations)
What are the Risk Factors for Hereditary Elliptocytosis? (Predisposing Factors)
The risk factors for Hereditary Elliptocytosis include the following:
- A family history of Hereditary Elliptocytosis is a key risk factor, since it is a hereditary condition
- Being of Southeast Asian or European descent may place one at a higher risk for certain types of HE, than others
It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases one's chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.
Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.
What are the Causes of Hereditary Elliptocytosis? (Etiology)
Hereditary Elliptocytosis is a congenital genetic disorder that is inherited in an autosomal dominant fashion in a majority of individuals. It is stated to be caused by a deletion in a gene on chromosome 17.
- This deletion is what causes the red blood cells to become more oval in shape, as opposed to the circular shape associated with normal red blood cells
- A variety of proteins can be affected due to the mutation(s)
- This deleted gene is present in families with a history of the condition
There is a subtype of Hereditary Elliptocytosis, known as Hereditary Pyropoikilocytosis, which is autosomal recessive. It is usually seen among individuals of African descent. Severe signs and symptoms may be observed due to the presence of severe hemolytic anemia.
Autosomal dominant: Autosomal dominant conditions are traits or disorders that are present when only one copy of the mutation is inherited on a non-sex chromosome. In these types of conditions, the individual has one normal copy and one mutant copy of the gene. The abnormal gene dominates, masking the effects of the correctly function gene. If an individual has an autosomal dominant condition, the chance of passing the abnormal gene on to their offspring is 50%. Children, who do not inherit the abnormal gene, will not develop the condition or pass it on to their offspring.
What are the Signs and Symptoms of Hereditary Elliptocytosis?
The signs and symptoms of Hereditary Elliptocytosis may include:
- In infants, anemia (lack of healthy red blood cells) and jaundice may be observed
- Anemia can lead to pale skin, tiredness, increased heart rate, shortness of breath, and dizziness
- Jaundice causes yellow discoloration of the skin
- A vast majority of individuals (nearly 90%) do not show any signs and symptoms. Hence, the condition is often underdiagnosed
How is Hereditary Elliptocytosis Diagnosed?
Hereditary Elliptocytosis may be diagnosed in the following manner:
- A complete physical examination and evaluation of family medical history, with information on any previous incidence of HE in the family
- Blood tests that include:
- Complete blood count to measure the various components of blood
- Blood smear test to determine blood cell shape
- Bilirubin level test to determine levels of bilirubin in the body (which causes yellowing of the skin and eye white)
- Lactate dehydrogenase (LDH) test
- Serum hemoglobin electrophoresis
- Osmotic fragility test
- Abdominal ultrasound scan
- Hereditary Elliptocytosis can be confirmed by the presence of genetic material in a blood sample; there are a number of genes that are linked to the condition
Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.
What are the possible Complications of Hereditary Elliptocytosis?
The complications of Hereditary Elliptocytosis may include:
- Abnormalities in the kidney
- Formation of gallstones
- Associated vitamin B12, folate, iron deficiencies in the individuals can make the condition worse
- Splenectomy (surgical removal of spleen) can cause complications, such as blood clot in the vein, infections, lung collapse, or injury to adjacent organs during surgery
- Severe HE can result in growth retardation and short stature
How is Hereditary Elliptocytosis Treated?
Hereditary Elliptocytosis is an incurable genetic disorder. However, in a majority of individuals, no treatment may be necessary. In some children or adults, the treatment for significant signs and symptoms may include:
- Blood transfusion, if there is a severe lack of healthy red blood cells
- Splenectomy (removal of the spleen) may be performed to treat Hereditary Elliptocytosis
- Surgery to remove gallbladder, in case of gallstones that present significant symptoms
- Individuals with the following vitamin and mineral deficiencies may require suitable supplementation:
- Iron deficiency
- Folate deficiency
- Vitamin B12 deficiency
- Folic acid supplementation or a diet rich in folic acid can be used to avoid complications of folate deficiency associated with the condition
How can Hereditary Elliptocytosis be Prevented?
Currently, there are no specific methods or guidelines to prevent Hereditary Elliptocytosis, since it is a genetic condition.
- Genetic testing of the expecting parents (and related family members) and prenatal diagnosis (molecular testing of the fetus during pregnancy) may help in understanding the risks better during pregnancy
- If there is a family history of the condition, then genetic counseling will help assess risks, before planning for a child
- Active research is currently being performed to explore the possibilities for treatment and prevention of inherited and acquired genetic disorders such as Hereditary Elliptocytosis
The following factors may be considered to control severity of the signs and symptoms:
- Eating a healthy and well-balanced diet to avoid any vitamin and mineral deficiency disorders
- Administration of pneumococcal vaccinations for individuals whose spleen is removed, as they are prone to infections
- Regular medical screening at periodic intervals with tests, scans and physical examinations are mandatory
What is the Prognosis of Hereditary Elliptocytosis? (Outcomes/Resolutions)
- The prognosis of Hereditary Elliptocytosis is good, if the condition is diagnosed early and appropriate treatment provided
- Uncontrolled Hereditary Elliptocytosis with complications can lead to a poor prognosis
Additional and Relevant Useful Information for Hereditary Elliptocytosis:
The following links may help you understand various related conditions: