An 8-year-old child who is a known case of B-thalassemia major on repeated blood transfusion is presenting with typical facial features comprising of frontal bossing, depressed cranial vault, maxillary widening, with saddle nose. On examination, he was found to be icteric Peripheral smear shows typical hypochromic microcytic anemia with teardrop-shaped RBC.
Children with typical “Chipmunk facies” in thalassemia
Q.1. What is the etiopathogenesis of thalassemia?
Q.2. How many clinical variants of thalassemia exist?
Q.3. What is the name given to specific facies of this child?
Ans 1. Thalassemia is due to defect in biosynthesis of a or B-globin chain synthesis resulting in unbalanced accumulation of B and a-globin chain respectively. This is respectively called a-thalassemia and B-thalassemia.
The mutation which causes B-thalassemia may affect any of the following globin chain synthesis impairing its production:
a. Transcription of gene
b. Post-transcriptional modification of mRNA
d. Post-translational modification
In most cases it is either the defect in splicing of mRNA or premature termination of translation.
Ans 2. B-thalassemia may be homozygous or heterozygous. There are three clinical variants of homozygous ß-thalassemia based on severity of presentation:
a. Thalassemia major
b. Thalassemia intermedia
c. Thalassemia minor
B-thalassemia minor is mild and usually asymptomatic, the only manifestation is hypochromic, microcytic anemia. B-thalassemia major patients are born healthy but they become symptomatic with anemia, hepatosplenomegaly, growth retardation, jaundice and bone changes which usually develop within the first year of life, thus making regular blood transfusion and iron chelation therapy necessary for survival.