The Importance of Molecular Biological Analysis for the Laboratory Diagnostic of Homozygous Haemoglobin Malay.

Haemoglobin (Hb) Malay is variant haemoglobin with a β⁺⁺ thalassemia phenotype. The prevalence of Hb Malay in the Malaysian population was 5.5%. We describe a 58-year-old male who presented with symptomatic anaemia to the Hospital Universiti Sains Malaysia. Further history revealed that the patient had anaemia since the age of 28, and on regular follow-up at other hospital. Physical examination revealed pallor, jaundice and hepatosplenomegaly. The full blood count and peripheral blood smear showed hypochromic microcytic anaemia with anisopoikilocytosis, and many target cells. High-performance liquid chromatography results showed a β thalassemia trait. However, the diagnosis does not alight with the patient's condition. Bone marrow aspirate was completed and showed reactive changes and erythroid hyperplasia. A molecular test was then performed for β globin gene mutation detection using Multiplex Amplification Refractory Mutation System (M-ARMS) PCR method. This revealed the result as homozygous codon 19 mutation or Hb Malay. Therefore, in this case report we would like to highlight the laboratory approaches, the challenges faced by the usual haematological investigations and the importance role of molecular testing in the diagnosis of severe anaemia.