title: Beta thalassaemia in Nigeria: myth or fact?
abstract: BACKGROUND
  The high prevalence of sickle cell disorders and the mild deletional á-thalassaemia among Nigerians is well known, but â-thalassaemia is believed to be almost nonexistent. Beta thalassaemia trait (BTT) was screened for in patients with unexplained recurrent haemolytic anaemia and healthy individuals.
  
  
  METHODS
  â-thalassaemia trait (BTT) was screened for using MCH and HbA2 of 27 pg and 3.5% respectively as cut off in 151 Nigerians which included 29 patients and 122 apparently healthy individuals. The subjects were categorized into four, Group I (high HbA2, low MCH), Group II (low HbA2 and MCH), Group III (high HbA2 and high/normal MCH) and Group IV (normal HbA2 and MCH).
  
  
  RESULTS
  Group I are possible carriers of BTT while group IV are least likely to carry either alpha or beta thalassaemia genes. There were 36 (26%), 39 (28%), 27 (19%) and 38 (27%) in groups I-IV respectively. The mean MCH, MCV, haematocrit and HbA, for the study population were 26 +/- 2.8, 81 +/- 7.9, 37.5 +/- 6.8 and 3.4 +/- 1.7 respectively. The mean MCV and haematocrit were significantly lower for group I compared to group IV (76.9 Vs. 86.6, p=0.00) and (36.5Vs39.7, p=0.03) respectively. Group II had significantly lower MCV and haematocrit than group IV (75.4 (p=0.00) and 36.4 (p=0.01) respectively. There was a positive correlation between the MCH and MCV with the haematocrit (p=0.004, p=0.001 respectively) but HbA2 showed a stronger negative correlation with the haematocrit (p<0.0001).
  
  
  CONCLUSIONS
  This does not only show the presence of BTT, but a higher prevalence than previously thought, mutations responsible for it should therefore be characterized.
authors.affiliation: Department of Haematology, College of Medicine, University of Ibadan, Ibadan, Nigeria. tkotila@comui.edu.ng
authors.forename: T R
authors.initials: TR
authors.lastname: Kotila
mesh_terms: D004247:DNA / Q000032:analysis*; D004909:Erythrocyte Indices / Q000235:genetics*; D006454:Hemoglobins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D009549:Nigeria / Q000453:epidemiology; D010641:Phenotype; D015995:Prevalence; D017086:beta-Thalassemia / Q000097:blood / Q000453:epidemiology* / Q000235:genetics
chemical_list: D006454:Hemoglobins; D004247:DNA