Thalassemia – thalassemia major, thalassemia minor
Hemoglobin is found inside red blood cells and its role is to transport oxygen through blood to tissues. Hemoglobin structure is supported by two types of protein chains – four globin.
Normal globins of hemoglobin are: – 2 alpha chains and 2 beta chains in adult hemoglobin (Hb A1) 97-98% of total – 2 chains alpha and 2 delta chains in 2-3% of adult hemoglobin (Hb A2) – and 2 alpha chains and 2 gama chains in newborn hemoglobin (Hb F).
In thalassemia, the synthesis of a globin chain is reduced and replaced with the complementary chain. Therefore, is affected the quantity and quality of hemoglobin. This causes red blood cell degradation and thus leads to anemia and lack of oxygen to tissues.
Types of thalassemia and symptoms
1. Beta thalassemia major (Cooley’s anemia, Mediterranean anemia, thalassemia major):
– There is a decreased production or absence of beta chains because they are replaced with gamma chains (Hb F);
– It is transmitted genetically, homozygous (both parents must carry the gene and not necessarily sick);
– Has a frequency of 5% of the population.
- insidious onset after age of 6-7 months by progressive mucocutaneous pallor, jaundice, skin hemochromatosis, decreased appetite, weight deficit, enlarged abdomen, enlarged liver and spleen;
Clinically, children with thalassemia major have a specific mongoloid facies with skull tower-like, muscle hypotrophy.
Complications in thalassemia major: hemochromatosis (iron deposition in tissues after hemoglobin degradation), liver (fibrosis, cirrhosis), myocardial (congestive heart failure, arrhythmias, death), chronic relapsing pericarditis, endocrine glands (diabetes, insufficient endocrine, pubertal retardation ), muscle (myopathy), low resistance to infection after spleenectomy, bone fractures, gallstones, trophic disorders (leg ulcers).
Treatment of thalassemia major: infusion with blood at 3-4 weeks accompanied by chelators of excess iron (Desferal) in 5-6 doses a week, folic acid and vaccin for hepatitis. In cases where the spleen is too large and painful or transfusion requirements are exceeded there is indicated spleenectomy (spleen removal). This intervention may have infectious complications, which is why antibiotic prophylaxis is therefore recommended.
2. Beta thalassemia minor (thalassemia minor)
– Consists in an increase of hemoglobin A2 (delta chains instead of gamma) with more than 3.5%.
– The disease is transmitted directly from one parent, patients are carriers of a single gene. By reproducing with a partner with the same gene can give birth to a child with beta thalassemia major.
– Only 25-30% of patients have mild symptoms of thalassemia minor: mild anemia with discrete pallor and moderately enlarged spleen.
– You do not need treatment, but iron preparations are contraindicated.
3. Alpha thalassemia – is affected the synthesis of alpha globin chains which are replaced by gamma or delta chains.
– In the heterozygous form (minor) of thalassemia symptoms are represented by mild anemia and homozygous form is incompatible with life.