Background and objective: Unstable hemoglobins (Hb) show amino acid substitutions in critical places that produce a decrease of molecular solubility facilitating its denaturalization and precipitation. We describe the first case of Hb Newcastle in Spain.
Case report: 5 year-old girl who came to visit due to fever over 4 days. Physical examination disclosed pale skin with subicteral mucosaes and splenomegaly. Lab analysis disclosed: Hb, 79 g/l; haematocrit, 0.27 l/l, mean corpuscular volume 93.4 fl, and reticulocyte count of 3%, along with anysocytosis and polychromasia.
Results: Hemoglobin heat stability test was positive. Hemoglobin electrophoresis showed a low band at HbA2. High performance liquid chromatography (HPLC) showed an Hb peak corresponding to the 12% of total Hb. Beta globin gene sequentiation showed the CD92 His --> Pro mutation Hb Newcastle in heterocygote condition in patient and her mother.
Conclusions: Hb Newcastle has been described in 3 patients of English, Russian and Chinese origin. Clinical manifestation is chronic hemolytic anemia with severe crisis after oxidant drugs ingestion or infections. By using the electrophoretic method, a diffuse pattern of Hb bands between HbA and HbA2 is observed, difficulting the precise identification of the abnormal Hb. This inconvenience is overcomed by using HPLC that allows the clear identification of the abnormal Hb Newcastle.