Ballana Guix, EsterGonzález Ruiz, Juan RamónBosch Pagès, NinaEstivill, Xavier, 1955-2014-12-222014-12-222007Ballana E, González J, Bosch N, Estivill X. Inter-population variability of DEFA3 gene absence: correlation with haplotype structure and population variability. BMC Genomics. 2007 Jan;8:14. DOI: 10.1186/1471-2164-8-141471-2164http://hdl.handle.net/10230/23019Background: Copy number variants (CNVs) account for a significant proportion of normal phenotypic variation and may have an important role in human pathological variation. The α-defensin cluster on human chromosome 8p23.1 is one of the better-characterized CNVs, in which high copy number variability affecting the DEFA1 and DEFA3 genes has been reported. Moreover, the DEFA3 gene has been found to be absent in a significant proportion of control population subjects. CNVs involving immune genes, such as α-defensins, are possibly contributing to innate immunity differences observed between individuals and influence predisposition and susceptibility to disease. Results: We have tested the DEFA3 absence in 697 samples from different human populations. The proportion of subjects lacking DEFA3 has been found to vary from 10% to 37%, depending on the population tested, suggesting differences in innate immune function between populations. Absence of DEFA3 was correlated with the region's haplotype block structure. African samples showed a higher intra-populational variability together with the highest proportion of subjects without DEFA3 (37%). Association analysis of DEFA3 absence with 136 SNPs from a 100-kb region identified a conserved haplotype in the Caucasian population, extending for the whole region. Conclusion: Complexity and variability are essential genomic features of the α-defensin cluster at the 8p23.1 region. The identification of population differences in subjects lacking the DEFA3 gene may be suggestive of population-specific selective pressures with potential impact on human health.application/pdfeng© 2007 Ballana et al; licensee BioMed Central Ltd. /nThis 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.GenomesImmunitatinfo:eu-repo/semantics/articlehttp://dx.doi.org/10.1186/1471-2164-8-14info:eu-repo/semantics/openAccess