Homozygosity for HBA1: c.179G > A: Hb Adana in an Infant

Hb Adana (HBA1: c.179G > A) is a very rare, unstable form of alpha-globin variant that results from deficient synthesis of functional alpha chains. We present a 2-month-old boy with hypochromic microcytic anemia, and remarkable anisocytosis, target cells and basophilic stippling on his peripheral blood smear. alpha-Globin gene analysis of the patient determined homozygosity for HBA1: c.179G > A, a mutation known as Hb Adana. On his follow-up visit, hemoglobin (Hb) levels were stable at 9.0-9.5 g/dL and mean corpuscular volume (MCV) was 62.2-62.5 fL without the need for a blood transfusion. Clinical and hematological findings of our case were comparable to Hb H (beta 4) or beta-thalassemia intermedia (beta-TI)-like phenotypes, despite the fact that he carried an alpha 1 gene mutation. Heterozygosity for the HBA1: c.179G4A mutation may also lead to microcytosis only as seen in his parents. According to our current knowledge, this is the first described case with homozygosity for the Hb Adana mutation, carried on the alpha 1 gene. The relatively mild presentation of the case highlights the milder phenotypic consequences of nondeletional alpha mutations in the alpha 1 vs. the alpha 2 gene.