Interactions between genetic admixture, ethnic identity, APOE genotype and dementia prevalence in an admixed Cuban sample; a cross-sectional population survey and nested case-control study

BMC Medical Genetics

Research Article

Juan J Llibre Rodríguez¹  Martin J Prince²  Cleusa P Ferri²  Adolfo Valhuerdi Cepero A³  Beatriz Marcheco Teruel⁴  Teresa Collazo Mesa T⁴  Evelyn Fuentes⁴  Paul McKeigue⁵  Milagros A Guerra Hernandez⁶  John RM Copeland JRM⁷ 

[1] Higher Institute of Medical Sciences of Havana, Cuba;Institute of Psychiatry, Centre for Global Mental Health, King's College, London, UK;Medical Sciences University of Matanzas, Matanzas, Cuba;National Centre for Medical Genetics, Havana, Cuba;Public Health Sciences section, University of Edinburgh Medical School, Edinburgh, UK;University Policlinic "27 de Noviembre", Havana, Cuba;University of Liverpool, Liverpool, UK;

关键词: Dementia;    Ethnic Identity;    APOE Genotype;    African Ancestry;    Dementia Diagnosis;   

DOI  :  10.1186/1471-2350-12-43

 received in 2010-11-25, accepted in 2011-03-24,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundThe prevalence and incidence of dementia are low in Nigeria, but high among African-Americans. In these populations there is a high frequency of the risk-conferring APOE-e4 allele, but the risk ratio is less than in Europeans. In an admixed population of older Cubans we explored the effects of ethnic identity and genetic admixture on APOE genotype, its association with dementia, and dementia prevalence.MethodsA cross-sectional catchment area survey of 2928 residents aged 65 and over, with a nested case-control study of individual admixture. Dementia diagnosis was established using 10/66 Dementia and DSM-IV criteria. APOE genotype was determined in 2520 participants, and genetic admixture in 235 dementia cases and 349 controls.ResultsMean African admixture proportions were 5.8% for 'white', 28.6% for 'mixed' and 49.6% for 'black' ethnic identities. All three groups were substantially admixed with considerable overlap. African admixture was linearly related to number of APOE-e4 alleles. One or more APOE-e4 alleles was associated with dementia in 'white' and 'black' but not 'mixed' groups but neither this, nor the interaction between APOE-e4 and African admixture (PR 0.52, 95% CI 0.13-2.08) were statistically significant. Neither ethnic identity nor African admixture was associated with dementia prevalence when assessed separately. However, considering their joint effects African versus European admixture was independently associated with a higher prevalence, and 'mixed' or 'black' identity with a lower prevalence of dementia.ConclusionsAPOE genotype is strongly associated with ancestry. Larger studies are needed to confirm whether the concentration of the high-risk allele in those with African ancestry is offset by an attenuation of its effect. Counter to our hypothesis, African admixture may be associated with higher risk of dementia. Although strongly correlated, effects of admixture and ethnic identity should be distinguished when assessing genetic and environmental contributions to disease risk in mixed ancestry populations.

【 授权许可】

Unknown   
© Teruel et al; licensee BioMed Central Ltd. 2011. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.