Thalassemia is an inherited blood disorder caused by the inability of the body to make enough hemoglobin. Thalassemia is most prevalent in Asia , Africa and the Mediterranean region. But, due to migration, the disease has become a global one. It is a major public health burden that is underrecognized and under-addressed, even in areas of high prevalence.
CAUSE
Thalassemia is an inherited condition where the body is unable to make enough hemoglobin due to a mutation in the gene responsible for hemoglobin production. (Hemoglobin is the main protein inside red blood cells. Its major function is to transport oxygen to all tissues of the body.) The decreased hemoglobin levels in the red blood cells of an individual with thalassemia result in reduced oxygen delivery to tissues.
There are 2 main types of thalassemia:
Alpha Thalassemia: where the body makes very few or no alpha globin chains.
Beta Thalassemia: where the body makes very few or no beta globin chains.
Hereditary
Thalassemia is an autosomal recessive disease. This means that for a child to be born with thalassemia, he or she has two ‘thalassemia genes’, one from each parent. Those who inherit only one thalassemia gene, are called carriers ( or said to have the thalassemia trait).
Patients with severe disease: early onset symptoms, including severe pallor, yellow eyes, dark-colored urine; decreased appetite, tiredness and dizziness, headaches, breathing difficulties, or irregular heartbeat. If not diagnosed and treated early, facial and bony deformities, a bulging abdomen due to hepatosplenomegaly (large spleen and liver), and often die in the first decade of life from severe anemia and heart failure.
Patients with moderate disease: moderate anemia and late onset of symptoms. With advancing age, however, they may develop a series of complications including leg ulcers, silent strokes, hypercoagulability, pulmonary hypertension, and iron overload.
Carriers are usually asymptomatic but can pass the thalassemia gene onto their offspring. Carriers may have mild anemia and can live normal lives.
Diagnosis
Diagnosis of thalassemia is based on:
Typical clinical presentation
Presence of chronic hemolytic anemia
Abnormal hemoglobin assay levels
Thalassemia changes on blood smear
Genetic studies showing the thalassemia mutation
Treatment
All patients should receive education, genetic counseling, and needed treatment with regular monitoring.
Treatment for carriers involves lifestyle management and genetic counseling.
Treatment plans for diagnosed thalassemia patients are individualized to the patient and will be recommended by the managing health care professional. Options for managing symptomatic thalassemia include packed red blood cell transfusions and iron chelation, bone marrow transplant, medications to aid red blood cell development and spleen removal.
Promising gene therapy trials for thalassemia are underway, awaiting long-term safety data.
PROGNOSIS
With early diagnosis and introduction of appropriate treatment, patients with thalassemia have high survival rates and good quality of life. With bone marrow transplantation and other emerging therapies, the prospect of a cure for thalassemia is high. Sadly, however, thousands of those living with thalassemia and across all age groups do not have access to such promising treatment.
PREVENTION
Thalassemia prevention programs include increasing public awareness, screening of carriers, genetic counseling to help couples make reasonably informed choices and availability of preimplantation and prenatal diagnoses. These programs have been shown to be cost-effective but are only adopted in a few countries. There are major differences in cultural, religious, ethical, and legal considerations regarding these prevention programs amongst different countries and within communities. Such differences need to be taken into consideration while planning any thalassemia prevention program.
