title: An investigation of the protective effect of alpha+-thalassaemia against severe Plasmodium falciparum amongst children in Kumasi, Ghana.
abstract: BACKGROUND
  Several factors influence the severity of Plasmodium falciparum; here, we investigate the impact of alpha+-thalassaemia genotype on P. falciparum parasitemia and prevalence of severe anaemia amongst microcytic children from Kumasi, Ghana.
  
  
  METHODS
  Seven hundred and thirty-two children (≤10 years) with P. falciparum were categorised into normocytic and microcytic (mean cell volume ≤76 fL). Microcytic individuals were genotyped for the -α(3.7) deletional thalassaemia mutation and parasite densities determined.
  
  
  RESULTS
  Amongst microcytic patients both parasite densities and prevalence of severe malaria parasitemia (≥100 000/μL) were significantly lower (P < 0.001) in the presence of an alpha+-thalassaemia genotype compared with non-alpha+-thalassaemia genotype. There was no evidence that alpha+-thalassaemia protected against severe anaemia. The protection conferred by alpha-thalassaemia genotype against severe P. falciparum parasitemia did not change with increasing age.
  
  
  CONCLUSIONS
  The severity of P. falciparum parasitemia was significantly lower in both the homozygous and heterozygous alpha+-thalassaemia groups compared with microcytic individuals with non-alpha+-thalassaemia genotype. The protective effect, from severe malaria, of the alpha+-thalassaemia allele does not alter with age.
authors.affiliation: Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.|University of Westminster, School of Life Sciences, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Opoku-Okrah
authors.affiliation: University of Westminster, School of Life Sciences, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Gordge
authors.affiliation: Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: E
authors.initials: E
authors.lastname: Kweku Nakua
authors.affiliation: Kwame Nkrumah University of Science and Technology, Kumasi, Ghana.
authors.forename: T
authors.initials: T
authors.lastname: Abgenyega
authors.affiliation: University of Westminster, School of Life Sciences, London, UK.
authors.forename: M
authors.initials: M
authors.lastname: Parry
authors.affiliation: University of Westminster, School of Life Sciences, London, UK.
authors.forename: C
authors.initials: C
authors.lastname: Robertson
authors.affiliation: University of Westminster, School of Life Sciences, London, UK.
authors.forename: C L
authors.initials: CL
authors.lastname: Smith
mesh_terms: D002648:Child; D002675:Child, Preschool; D004909:Erythrocyte Indices; D004912:Erythrocytes / Q000469:parasitology* / Q000473:pathology; D005260:Female; D015870:Gene Expression; D005838:Genotype; D005869:Ghana; D006579:Heterozygote; D006720:Homozygote; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D016778:Malaria, Falciparum / Q000097:blood / Q000235:genetics* / Q000469:parasitology / Q000473:pathology; D008297:Male; D018512:Parasitemia / Q000097:blood / Q000235:genetics* / Q000473:pathology; D010963:Plasmodium falciparum / Q000502:physiology; D015995:Prevalence; D065840:Protective Factors; D012720:Severity of Illness Index; D055542:alpha-Globins / Q000172:deficiency / Q000235:genetics*; D017085:alpha-Thalassemia / Q000097:blood / Q000235:genetics* / Q000469:parasitology / Q000473:pathology
chemical_list: D055542:alpha-Globins
keywords: Malaria; West Africa; alpha thalassemia; microcytosis; severe anaemia