Hi Manal,
Thalassemia is basically an amino acid problem. It is missing or substituted amino acids in the genes that cause them to malfunction. Is this doctor suggesting there is some way to correct this?
It is not yet possible to accurately predict the outcome of a patient based solely on the thal mutations. Other genes can come into play and the ability to produce fetal hemoglobin can be a significant factor in the ultimate Hb level an intermedia can maintain. For a review of this topic please see
http://www.eae.gr/haema/pdf/94-03.pdf...it is difficult to
predict the phenotype from the genotype because of the
variable effects of the modifier genes.
A similar study by Rund et al18 classified patients according
to their mutations as mild, moderate and severe.
There were 8 families who were homozygous or compound
heterozygotes for two moderate mutations. Most of the
individuals manifested a severe phenotype. However, four
patients had only moderate anaemia and did not require
transfusion. The second set of patients who had one severe
and one moderate mutation had a moderately severe
phenotype. The high HbF levels to some extent attenuated
the severity of the disease. In the third group of
patients with two severe mutations, all the patients were
symptomatic with a moderately severe phenotype. The
HbF levels were extremely high in all these patients.
It can be seen that presence of two severe or one moderate
and one severe allele need not necessarily lead to a
severe form of รข thalassaemia. It is possible that other
modifiers interact with the genes to alter the phenotype.
The ability of a patient to produce fetal hemoglobin is a moderating factor that should be looked at along with other genes, when attempting to explain the effects of thalassemia mutations. The hemoglobin gene mutations alone can not be used to predict the severity of the thalassemia.