2014

Ezalia Esa, Tan Jen Ern, Rahimah Ahmad, Nur Aisyah Aziz, Zubaidah Zakaria and Azlinda Abu Bakar (2014). A rare case of compound heterezygous haemaglobin Q-Thailand and haemaglobin Adana. International Journal of Health Sciences and Research 4(10): 327-332

We report a 15-year-old Malay girl who since the age of five required infrequent blood transfusions. However over the past 10 years, her transfusion requirements increased due to symptomatic anaemia. Currently, she has become transfusion dependent. Her peripheral blood film was consistent with severe haemolytic anaemia and the H-inclusion test was negative. Her mother, who was 36-week pregnant, also had features of haemolytic anaemia (haemoglobin, Hb: 8.5 g/dl) but in a milder form. Her father had normal Hb level but raised red cell count. Both parents had negative H-inclusion test. Hb subtyping by cation exchange high performance liquid chromatography and capillary electrophoresis only revealed presence of Hb variant in the father and the daughter. The abnormal peak appeared at retention time 4.62 seconds (25.6%) and zone 7 (28.2%) in the father. Similar findings were observed in the daughter, but with lesser values (retention time 4.58 seconds, 15.1% and zone 7, 19.1%). Multiplex Gap PCR revealed that both of them were heterozygous for single α-globin gene deletion (α^-4.2). Further analysis of α₁- and α₂-globin gene by DNA sequencing had confirmed they were heterozygous for Hb Q-Thailand, and surprisingly, the daughter were also found to have heterozygous Hb Adana in α₂-globin gene. The inheritance of Hb Adana was then discovered when the mother was found to be heterozygous for α₂ Hb Adana by Mutiplex ARMS PCR. Compound heterozygosity of Hb Q-Thailand and Hb Adana, which is a highly unstable Hb variant, would explain the clinical phenotype that was manifested by the patient.