The contribution of α+–thalassaemia to anaemia in a Nigerian population exposed to intense malaria transmission

• Published in: Tropical medicine & international health Vol. 4; no. 4; pp. 302 - 307
• Main Authors: Mockenhaupt, Frank P., Falusi, Adeyinka G., May, Juergen, Ademowo, Olusegun G., Olumese, Peter E., Meyer, Christian G., Bienzle, Ulrich
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.04.1999; Blackwell Science
• Subjects: Adolescent; Adult; Age Distribution; alpha-Thalassemia - blood; alpha-Thalassemia - complications; alpha-Thalassemia - epidemiology; alpha-Thalassemia - genetics; alpha‐thalassaemia; anaemia; Anemia, Hypochromic - epidemiology; Anemia, Hypochromic - etiology; Biological and medical sciences; Child; Child, Preschool; Erythrocyte Indices; Gene Frequency; Genetic Carrier Screening; Genotype; Globins - genetics; Hemoglobins - analysis; Homozygote; Human protozoal diseases; Humans; Infant; Infectious diseases; Malaria; Malaria, Falciparum - complications; Malaria, Falciparum - epidemiology; Malaria, Falciparum - transmission; Medical sciences; Middle Aged; Nigeria; Nigeria - epidemiology; P. falciparum; Parasitic diseases; Population Surveillance; Prevalence; Protozoal diseases; Risk Factors; Tropical medicine; Nigeria; Africa; Human; Hemoglobinopathy; Protozoal disease; Malaria; Anemia; Hemopathy; Parasitosis; Statistical study; Genetic disease; Infection; Hemolytic anemia; Association; α-Thalassemia
• ISSN: 1360-2276; 1365-3156
• DOI: 10.1046/j.1365-3156.1999.00386.x

Summary The proportion to which α‐thalassaemia contributes to anaemia in Africa is not well recognized. In an area of intense malaria transmission in South‐West Nigeria, haematological parameters of α‐thalassaemia were examined in 494 children and 119 adults. The –α3.7 type of α+‐thalassaemia was observed at a gene frequency of 0.27. Nine and 36.5% of individuals were homozygous and heterozygous, respectively. P.falciparum‐infection was present in 78% of children and in 39% of adults. The α‐globin genotypes did not correlate with the prevalence of P. falciparum‐infection. α+‐thalassaemic individuals had significantly lower mean values of haemoglobin, mean corpuscular volume, and mean corpuscular haemoglobin than non‐thalassaemic subjects. Anaemia was seen in 54.7% of children with a normal α‐globin genotype, in 69.9% of heterozygous (odds ratio: 1.99, 95% confidence interval: 1.32–3.00, P= 0.001), and in 88.4% of homozygous α+‐thalassaemic children (odds ratio: 7.72, 95% confidence interval: 2.85–20.90, P= 0.0001). The findings show that α+‐thalassaemia contributes essentially to mild anaemia, microcytosis, and hypochromia in Nigeria.