TY - JOUR T1 - Dominant β-thalassaemia with unusually high Hb A<sub>2</sub> and Hb F caused by β<sup>CD121(−G)</sup> (HBB:c.364delG) in exon 3 of β-globin gene JF - Journal of Clinical Pathology JO - J Clin Pathol SP - 511 LP - 513 DO - 10.1136/jclinpath-2019-206308 VL - 73 IS - 8 AU - Kritsada Singha AU - Rossarin Karnpean AU - Goonnapa Fucharoen AU - Supan Fucharoen Y1 - 2020/08/01 UR - http://jcp.bmj.com/content/73/8/511.abstract N2 - We describe a dominant β-thalassaemia caused by a deletion of G at nucleotide position 364 in exon 3 of the β-globin gene. The heterozygosity of this mutation was found in a 36-year-old Thai patient who had moderate hypochromic microcytic anaemia with haemolytic blood picture. Haemoglobin (Hb) analysis revealed relatively higher Hbs A2 (6.8%) and F (4.7%) as compared with those of β0-thalassaemia (n=278) and β+-thalassaemia (n=55) carriers in our series. Secondary structure prediction of the elongated β-globin chain showed that the α-helix at the C-terminal is disrupted dramatically by the random coil and β-sheet, which should result in a highly unstable β-globin variant, undetectable in peripheral blood and a dominant clinical phenotypic feature. ER -