Classification of 106 patients by phenotype and routine globin genotyping results
| Patient category | Case no. | MCV (fl) | MCH (pg) | HbA2 (%) | HbF (%) | Deletion detected by MLPA | |
| I | β-thalassaemia trait, no β-globin gene mutation detected | 4 | 60.0–83.5 | 19.6–27.8 | 4.0–5.8 | 0.3–1.0 | 0 |
| II | δβ-thalassaemia trait, no β-globin gene mutation detected | 8 | 59.6–79.8* | 17.5–27.5 | 2.3–2.8 | 6.8–21.8 | 4 |
| III | HPFH trait, no β-globin gene mutation detected | 10 | 63.1–112.2† | 20.4–38.0† | 1.0–3.5 | 5.2–64.5 | 1 |
| IV | β-thalassaemia trait with raised HbF, no β-globin gene mutation detected | 9 | 58.3–80.6 | 19.2–27.8 | 3.7–6.0 | 6.4–45.3 | 5 |
| V | β-thalassaemia trait with raised HbF, one common β-globin gene mutation detected | 16 | 58.3–75.3 | 17.8–26.7 | 1.6–6.6 | 6.9–90.0 | 0 |
| VI | β-thalassaemia intermedia/major, β-globin gene mutation detected in only one parent | 28 | 50.4–97.4‡ | 12.4–31.2‡ | 0.3–7.5 | 0.8–99.5‡ | 5 |
| VII | β-thalassaemia intermedia/major, presumably homozygous, no family study | 31 | 63.7–91.2‡ | 19.4–29.7‡ | 0.0–8.1 | 0.3–90.0‡ | 2 |
*Patient had concomitant iron deficiency anaemia.
†Two patients with low MCV had concomitant α-thalassaemia trait (−−SEA deletion); 1 patient with normal MCV and low MCH had heterozygous Hb Constant Spring mutation.
‡Most patients had received red cell transfusion.
MCH, mean corpuscular haemoglobin; MCV, mean corpuscular volume; MLPA, multiplex ligation-dependent probe amplification.