A Novel g.55040074delT in ALAS2 Gene Resulting in a Monomeric Protein and Severe Sideroblastic Anemia Phenotype.

Sideroblastic anemias are a rare group of disorders resulting from defective iron incorporation during heme synthesis and hence characterized by anemia and presence of ringed sideroblasts in bone marrow. The most common form is an X-linked disorder caused by mutations in ALAS2 gene. In the current paper, a case of X-linked sideroblastic anemia caused by a novel homozygous deletional mutation in exon 10 of ALAS2 gene is presented. The female infant developed moderately severe anemia at 6 months of age, which did not improve despite adequate nutritional support. The diagnosis was suspected considering a high plasma ferritin of 740.9 μg/L. The protein structure as predicted by SWISS model was a monomeric form rather than wild-type homodimer, resulting in marked loss of function and protein instability.