- Email: [email protected]
Population genetic data for 10 X-STR loci in autochthonous Basques from Navarre (Spain)
Forensic Science International: Genetics 6 (2012) e146–e148
Contents lists available at SciVerse ScienceDirect
Forensic Science International: Genetics journal homepage: www.elsevier.com/locate/fsig
Forensic Population Genetics—Short communication
Population genetic data for 10 X-STR loci in autochthonous Basques from Navarre (Spain) Marı´a Jose´ Illescas a, Alba Pe´rez a, Jose´ Marı´a Aznar a, Laura Valverde a, Sergio Cardoso a, Jaime Algorta b, Marian M. de Pancorbo a,* a b
BIOMICs Research Group, Centro de Investigacio´n ‘‘Lascaray’’ Ikergunea, Universidad del Paı´s Vasco UPV/EHU, Avda. Miguel de Unamuno 3, 01006 Vitoria-Gasteiz, Spain University of the Basque Country, Leioa, Spain
A R T I C L E I N F O
A B S T R A C T
Article history: Received 20 January 2012 Received in revised form 27 February 2012 Accepted 29 February 2012
Ten X chromosome markers (DXS6789, DXS6809, DXS7132, DXS7133, DXS7423, DXS8378, DXS9898, DXS9902, GATA172D05, and GATA31E08) were analyzed in a sample of 185 unrelated autochthonous Basques from Navarre. Deviations from Hardy–Weinberg equilibrium and linkage disequilibrium between markers were not observed at any loci. Combined power of discrimination was 0.999999999 (females) and 0.999998764 (males). Mean exclusion chance was 0.99999463 (trios) and 0.999761591 (duos). Pairwise genetic distances (Fst) of X-STR frequencies indicate significant differences in the allele frequency distribution between the autochthonous Basques from Navarre and American and Iberian populations except with the Basque Country. ß 2012 Elsevier Ireland Ltd. All rights reserved.
Keywords: X chromosome STR Autochthonous Basques
1. Population The autochthonous Basque population has been described as genetically isolated from other populations based on a variety of short-tandem repeat (STR) markers, such as autosomal STRs [1,2] and X-STRs [3]. Northern Navarre has a high percent of autochthonous Basque population that shares a cultural and language background with other Basque communities in Spain (Fig. 1). Navarre shares borders with France, and the Autonomous Communities of the Basque Country, La Rioja and Aragon. X chromosome short-tandem repeat (X-STR) assays are helpful in complex kinship testing cases where autosomal and Y chromosome analyses convey little information. X-STR analysis has the power of exclusion/inclusion needed to resolve an alleged mother–son/ father–daughter parentage and full and half-sibship [4]. The purpose of this study was to create a population database of autochthonous Basques from Navarre to obtain allelic frequencies and forensic efficiency parameters using an X-STR decaplex. At the same time, pairwise genetic distances were calculated to deter-
* Corresponding author. Present address: BIOMICs Research Group, University of the Basque Country, CIEA Centro de Investigacio´n y Estudios Avanzados ‘‘Lucio Lascaray’’, Avda. Miguel de Unamuno, 3, 01006 Vitoria-Gasteiz, Spain. Tel.: +34 945 01 4528; fax: +34 945 01 4458. E-mail addresses: [email protected] (M.J. Illescas), [email protected] (A. Pe´rez), [email protected] (J.M. Aznar), [email protected] (L. Valverde), [email protected] (S. Cardoso), [email protected] (J. Algorta), [email protected] (M.M. de Pancorbo). 1872-4973/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.fsigen.2012.02.014
mine the differences between the autochthonous Basque population from Navarre and other Iberian and American populations using the same 10 X-STR markers [3,5,6]. 1.1. Samples Mouthwash samples were collected from unrelated individuals in northern Navarre (Fig. 1). Only female donors with eight (N = 94) and male donors with even (N = 91) Basque last names were selected. Samples were collected following ethical requirements regarding the protection of personal data [7].
2. Methods 2.1. DNA extraction and quantification DNA was extracted with Gentra1 Puregene1 Kit (Qiagen, Hilden, Germany) for buccal cells from mouthwash, followed by dsDNA quantification with the Quant-iT PicoGreen1 dsDNA Assay Kit (Invitrogen, Carlsbad, CA) in a DTX880 Multimode Detector (Beckman Coulter, Fullerton, CA). 2.2. PCR amplification Amplification was performed using QIAGEN Multiplex PCR Kit and ten X-STR primer sets (DXS6789, DXS6809, DXS7132, DXS7133, DXS7423, DXS8378, DXS9898, DXS9902, GATA172D05, and GATA31E08) described in a previous study [5].
[(Fig._1)TD$IG]
M.J. Illescas et al. / Forensic Science International: Genetics 6 (2012) e146–e148
e147
Table 1 Pairwise genetic distances (Fst) and significance values for 10 X-STRs between a sample population of autochthonous Basques from Navarre and Iberian and American populations. Country
Region or province
Fst
p-Value
Spain
Basque Countrya Pas Valleya Cantabriab Galiciab Barcelonac
0.004 0.012* 0.006* 0.006* 0.007*
0.017 0.000 0.000 0.000 0.001
Portugal
North Portugalb Central Portugalb
0.010* 0.007*
0.000 0.000
Brazil
Mato Grosso du Sulb Sa˜o Paulob Rio de Janeirob Parana´b
0.013* 0.015* 0.026* 0.010*
0.000 0.000 0.000 0.000
Argentina
Misionesb Rio Negrob Co´rdobab Buenos Airesb
0.022* 0.018* 0.013* 0.009*
0.000 0.000 0.000 0.000
Colombia Costa Rica
Antioquiab Costa Ricab
0.020* 0.016*
0.000 0.000
Fig. 1. Distribution of samples collected from the autochthonous Basque population in Navarre.
2.3. Typing STR fragment separation and detection was performed with ABI1 Prism 3130 Genetic Analyzer (Applied Biosystems, Foster City, CA).
a b
2.4. Statistical analysis Allelic frequencies were calculated for 279 chromosomes. Heterozygosity, Hardy–Weinberg equilibrium (females), pairwise linkage disequilibrium (males) and pairwise genetic distances (Fst) were calculated using Arlequin software v3.11 [8] with available population databases for the same X-STR decaplex markers. Genetic distances were used to construct an unrooted neighborjoining tree using TreeFit [9] and visualized on TreeView [10]. Forensic efficiency parameters included: power of discrimination for males and females and expected paternity probability of exclusion [11] for duos and trios.
c
[(Fig._2)TD$IG]
*
Ref. [3]. Ref. [5]. Ref. [6]. Significant values (p < 0.005).
3. Results Allele frequencies and forensic efficiency parameters are shown in Table S1. Heterozygocity ranged from 0.6063 (DXS7133) to 0.8085 (GATA172D05). Deviations from Hardy–Weinberg equilibrium were not observed at any loci. Pairwise linkage disequilibrium between markers was not observed (p < 0.0011, significant level after Bonferroni correction). Acceptable levels of power of discrimination were determined, ranging from 78% to 94% for single locus analysis in females. Combined power of discrimination was 0.99999999 and 0.999998764 for females and males, respectively. A priori probability detection of error expectancy in paternity cases (mean exclusion chance) was 0.99999463 (trios) and 0.999761591 (duos). Pairwise genetic distances (Fst) (Table 1) between the sample population of autochthonous Basques from Navarre indicate significant differences (p < 0.005, after Bonferroni correction) with other Iberian populations (except the Basque Country) and American populations, being furthest from the Pas Valley in the Iberian Peninsula and Rio de Janeiro in South America. An unrooted neighgbor-joining (NJ) tree (Fig. 2) was generated based on pairwise Fst-values which locates the autochthonous Basques from Navarre closest to the Basque Country population.
Fig. 2. Neighbor-joining tree based on pairwise genetic distances (Fst) for 10 X-STR markers. NA, Navarre; BC, Basque Country; PV, Pas Valley; CA, Cantabria; BAR, Barcelona; GA, Galicia; NP, North Portugal; CP, Central Portugal; MG, Mato Grosso do Sul; SP, Sa˜o Paulo; RJ, Rio de Janeiro; PA, Parana´; MI, Misiones; RN, Rio Negro; CO, Co´rdoba; AN, Antioquia; CR, Costa Rica. Autochthonous populations from the Northern Iberian Peninsula appear underlined.
4. Discussion The 10 X-STRs employed for the development of the allele frequency database of autochthonous Basques from Navarre show ideal characteristics for their use in forensic and paternity testing, such as absence of departure from Hardy–Weinberg equilibrium and linkage disequilibrium, high power of discrimination in both
females and males, and high mean exclusion chance values for duos and trios. The unrooted NJ tree generated based on pairwise genetic distances (Fst) shows a clear separation of the autochthonous Basque population from Navarre from Iberian populations, being closer to other sources of isolated autochthonous Basque
e148
M.J. Illescas et al. / Forensic Science International: Genetics 6 (2012) e146–e148
populations like the Basque Country. These results point to an evident substructuring of Basque populations suggested by Pe´rezMiranda et al. [1] and Garcı´a-Obrego´n et al. [12]. Although small pairwise genetic distances were determined when compared to other Iberian populations, significant p-values were obtained. Gusma˜o et al. [5] found no significant differences between Galicia and Portugal suggesting a mixed genetic profile that accounts for the differences reflected in these results when compared to an isolated population. In this sense, the case of the autochthonous Basques from Navarre is similar to the case of the Pas Valley [3]. Similarly, compared to Northern and Central Portugal, low pairwise genetic distances (Fst-value) were determined. However, the Fst-value correction is not higher than 1%. Furthermore, the largest Fst compared to non-Iberian populations was 2.6%, indicating that whenever a specific population reference database is not available, a 2.6% Fst-value correction should be used [13]. In the case of Argentina, the low Fst-values found for Buenos Aires might be due to the mixed genetic profile of European ancestry due to increasing immigrant population from Spain and Italy that the country has seen since mid-1800s [14] as qualified industrial, craftsmanship and rural workers specialized in cattle raising [15]. However, further population comparisons must be performed when allelic frequencies for other Spanish populations become available in order to determine the need to use a regional or specific national population reference database for forensic testing calculations involving X chromosome markers. 5. Conclusions The X-STR decaplex allelic database created for the autochthonous Basques from Navarre has notable impact in complex paternity and sibship diagnoses given its robustness and high power of discrimination and exclusion rendered by highly polymorphic loci. 6. Quality control This paper follows the guidelines for publication of population data requested by the journal [16] and the International Society for Forensic Genetics (ISFG), as well as abiding to ISFG recommendations on the analysis of DNA polymorphisms [17]. Conflict of interest The authors declare no competing interest in the content of this manuscript. Acknowledgements We would like to thank the donors who made this study possible. This project was supported by the Government of the Basque Country (Grupo Consolidado IT-424-07). Research activities at the University of the Basque Country were partially supported by Erasmus Mundus External
Cooperation Window through the EMUNDUS20 project and the Basque Country Government through the Department of Education, Universities and Research. Technical and human support provided by SGIker (UPV/EHU, MICINN, GV/EJ, ESF) and Progenika Biopharma S.A. is gratefully acknowledged. We also thank the Navarre Health Service and Nafarroako Batzokiak for their collaboration.
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.fsigen.2012.02.014. References [1] A.M. Pe´rez-Miranda, M.A. Alfonso-Sa´nchez, A. Kalantar, S. Garcı´a-Obrego´n, M.M. de Pancorbo, J.A. Pen˜a, R.J. Herrera, Microsatellite data support subpopulation structuring among Basques, J. Hum. Genet. 50 (2005) 403–414. [2] F. Pe´rez-Lazaun, J. Calafell, E. Clarimo´n, E. Bosch, L. Mateu, L. Gusma˜o, A. Amorim, N. Benchemsi, J. Bertranpetit, Allele frequencies of 13 short tandem repeats in population samples from the Iberian Peninsula and Northern Africa, Int. J. Legal Med. 113 (2000) 208–214. [3] M.T. Zarrabeitia, F. Pinheiro, M.M. de Pancorbo, L. Caine´, S. Cardoso, L. Gusma˜o, J.A. Riancho, Analysis of 10 X-linked tetranucleotide markers in mixed and isolated populations, Forensic Sci. Int. Genet. 3 (2009) 63–66. [4] R. Szibor, M. Krawczak, S. Hering, J. Edlemann, E. Kuhlisch, D. Krause, Use of Xlinked markers for forensic purposes, Int. J. Legal Med. 117 (2003) 67–74. [5] L. Gusma˜o, P. Sa´nchez-Diz, C. Alves, I. Gomes, M.T. Zarrabeitia, M. Abovich, et al., A GEP-ISFG collaborative study on the optimization of an X-STR Decaplex: data on 15 Iberian and Latin American populations, Int. J. Legal Med. 123 (2009) 227–234. [6] B. Garcı´a, M. Crespillo, M. Paredes, J.L. Valverde, Population data for 10 Xchromosome STRs from north-east of Spain, Forensic Sci. Int. Genet. (2011), doi:10.1016/j.fsigen.2010.12.010. [7] Ley Orga´nica 15/1999 de Proteccio´n de Datos de Cara´cter personal BOE no. 29814, December 1999, pp. 43088–43099. www.boe.es/diario_boe/. [8] L. Excoffier, G. Laval, S. Schneider, Arlequin ver. 3.0: an integrated software package for population genetics data analysis, Evol. Bioinformatics Online 1 (2005) 47–50. [9] S.T. Kalinowski, TreeFit: a computer program for evaluating how well evolutionary trees fit genetic distance data, 2009. http://www.montana.edu/kalinowski. [10] R.D.M. Page, TreeView: an application to display phylogenetic trees on personal computers, Comput. Appl. Biosci. 12 (1996) 357–358. [11] D. Desmarais, Y. Zhong, R. Chakraborty, C. Perreault, L. Busque, Development of a highly polymorphic STR marker for identity testing purposes at the human androgen receptor gene (HUMARA), J. Forensic Sci. 43 (1998) 1046–1049. [12] S. Garcı´a-Obrego´n, M.A. Alfonso-Sa´nchez, A.M. Pe´rez-Miranda, M.M. de Pancrobo, J.A. Pen˜a, Polymorphic Alu insertions and the genetic structure of Iberian Basques, J. Hum. Genet. 52 (2007) 317–327. [13] K.L. Ayres, W.M. Powley, Calculating the exclusion probability and paternity index for X-chromosomal loci in the presence of substructure, Forensic Sci. Int. 149 (2005) 201–203. [14] V. Va´zquez de Prada, J.B. Amores, La emigracio´n de vascos y navarros al Nuevo Mundo y su repercusio´n en las comunidades de origen, in: La emigracio´n espan˜ola a Ultramar, 1492–1914, Tabapress, Espan˜a, 1991. [15] M.A. Salle Alonso, La emigracio´n espan˜ola en Ame´rica: historias y lecciones para el futuro, Editorial Fundacio´n Directa (2009). [16] A. Carracedo, J.M. Butler, L. Gusma˜o, W. Parson, L. Roewer, P.M. Schneider, Publication of population data for forensic purposes, Forensic Sci. Int. Genet. 4 (2010) 145–147. [17] W. Ba¨r, B. Brinkmann, B. Budowle, A. Carracedo, P. Gill, P. Lincoln, W. Mayr, B. Olaisen, DNA recommendations. Further report of the DNA Commission of the ISFH regarding the use of short tandem repeat systems, Int. J. Legal Med. 110 (1997) 175–176.
Contents lists available at SciVerse ScienceDirect
Forensic Science International: Genetics journal homepage: www.elsevier.com/locate/fsig
Forensic Population Genetics—Short communication
Population genetic data for 10 X-STR loci in autochthonous Basques from Navarre (Spain) Marı´a Jose´ Illescas a, Alba Pe´rez a, Jose´ Marı´a Aznar a, Laura Valverde a, Sergio Cardoso a, Jaime Algorta b, Marian M. de Pancorbo a,* a b
BIOMICs Research Group, Centro de Investigacio´n ‘‘Lascaray’’ Ikergunea, Universidad del Paı´s Vasco UPV/EHU, Avda. Miguel de Unamuno 3, 01006 Vitoria-Gasteiz, Spain University of the Basque Country, Leioa, Spain
A R T I C L E I N F O
A B S T R A C T
Article history: Received 20 January 2012 Received in revised form 27 February 2012 Accepted 29 February 2012
Ten X chromosome markers (DXS6789, DXS6809, DXS7132, DXS7133, DXS7423, DXS8378, DXS9898, DXS9902, GATA172D05, and GATA31E08) were analyzed in a sample of 185 unrelated autochthonous Basques from Navarre. Deviations from Hardy–Weinberg equilibrium and linkage disequilibrium between markers were not observed at any loci. Combined power of discrimination was 0.999999999 (females) and 0.999998764 (males). Mean exclusion chance was 0.99999463 (trios) and 0.999761591 (duos). Pairwise genetic distances (Fst) of X-STR frequencies indicate significant differences in the allele frequency distribution between the autochthonous Basques from Navarre and American and Iberian populations except with the Basque Country. ß 2012 Elsevier Ireland Ltd. All rights reserved.
Keywords: X chromosome STR Autochthonous Basques
1. Population The autochthonous Basque population has been described as genetically isolated from other populations based on a variety of short-tandem repeat (STR) markers, such as autosomal STRs [1,2] and X-STRs [3]. Northern Navarre has a high percent of autochthonous Basque population that shares a cultural and language background with other Basque communities in Spain (Fig. 1). Navarre shares borders with France, and the Autonomous Communities of the Basque Country, La Rioja and Aragon. X chromosome short-tandem repeat (X-STR) assays are helpful in complex kinship testing cases where autosomal and Y chromosome analyses convey little information. X-STR analysis has the power of exclusion/inclusion needed to resolve an alleged mother–son/ father–daughter parentage and full and half-sibship [4]. The purpose of this study was to create a population database of autochthonous Basques from Navarre to obtain allelic frequencies and forensic efficiency parameters using an X-STR decaplex. At the same time, pairwise genetic distances were calculated to deter-
* Corresponding author. Present address: BIOMICs Research Group, University of the Basque Country, CIEA Centro de Investigacio´n y Estudios Avanzados ‘‘Lucio Lascaray’’, Avda. Miguel de Unamuno, 3, 01006 Vitoria-Gasteiz, Spain. Tel.: +34 945 01 4528; fax: +34 945 01 4458. E-mail addresses: [email protected] (M.J. Illescas), [email protected] (A. Pe´rez), [email protected] (J.M. Aznar), [email protected] (L. Valverde), [email protected] (S. Cardoso), [email protected] (J. Algorta), [email protected] (M.M. de Pancorbo). 1872-4973/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.fsigen.2012.02.014
mine the differences between the autochthonous Basque population from Navarre and other Iberian and American populations using the same 10 X-STR markers [3,5,6]. 1.1. Samples Mouthwash samples were collected from unrelated individuals in northern Navarre (Fig. 1). Only female donors with eight (N = 94) and male donors with even (N = 91) Basque last names were selected. Samples were collected following ethical requirements regarding the protection of personal data [7].
2. Methods 2.1. DNA extraction and quantification DNA was extracted with Gentra1 Puregene1 Kit (Qiagen, Hilden, Germany) for buccal cells from mouthwash, followed by dsDNA quantification with the Quant-iT PicoGreen1 dsDNA Assay Kit (Invitrogen, Carlsbad, CA) in a DTX880 Multimode Detector (Beckman Coulter, Fullerton, CA). 2.2. PCR amplification Amplification was performed using QIAGEN Multiplex PCR Kit and ten X-STR primer sets (DXS6789, DXS6809, DXS7132, DXS7133, DXS7423, DXS8378, DXS9898, DXS9902, GATA172D05, and GATA31E08) described in a previous study [5].
[(Fig._1)TD$IG]
M.J. Illescas et al. / Forensic Science International: Genetics 6 (2012) e146–e148
e147
Table 1 Pairwise genetic distances (Fst) and significance values for 10 X-STRs between a sample population of autochthonous Basques from Navarre and Iberian and American populations. Country
Region or province
Fst
p-Value
Spain
Basque Countrya Pas Valleya Cantabriab Galiciab Barcelonac
0.004 0.012* 0.006* 0.006* 0.007*
0.017 0.000 0.000 0.000 0.001
Portugal
North Portugalb Central Portugalb
0.010* 0.007*
0.000 0.000
Brazil
Mato Grosso du Sulb Sa˜o Paulob Rio de Janeirob Parana´b
0.013* 0.015* 0.026* 0.010*
0.000 0.000 0.000 0.000
Argentina
Misionesb Rio Negrob Co´rdobab Buenos Airesb
0.022* 0.018* 0.013* 0.009*
0.000 0.000 0.000 0.000
Colombia Costa Rica
Antioquiab Costa Ricab
0.020* 0.016*
0.000 0.000
Fig. 1. Distribution of samples collected from the autochthonous Basque population in Navarre.
2.3. Typing STR fragment separation and detection was performed with ABI1 Prism 3130 Genetic Analyzer (Applied Biosystems, Foster City, CA).
a b
2.4. Statistical analysis Allelic frequencies were calculated for 279 chromosomes. Heterozygosity, Hardy–Weinberg equilibrium (females), pairwise linkage disequilibrium (males) and pairwise genetic distances (Fst) were calculated using Arlequin software v3.11 [8] with available population databases for the same X-STR decaplex markers. Genetic distances were used to construct an unrooted neighborjoining tree using TreeFit [9] and visualized on TreeView [10]. Forensic efficiency parameters included: power of discrimination for males and females and expected paternity probability of exclusion [11] for duos and trios.
c
[(Fig._2)TD$IG]
*
Ref. [3]. Ref. [5]. Ref. [6]. Significant values (p < 0.005).
3. Results Allele frequencies and forensic efficiency parameters are shown in Table S1. Heterozygocity ranged from 0.6063 (DXS7133) to 0.8085 (GATA172D05). Deviations from Hardy–Weinberg equilibrium were not observed at any loci. Pairwise linkage disequilibrium between markers was not observed (p < 0.0011, significant level after Bonferroni correction). Acceptable levels of power of discrimination were determined, ranging from 78% to 94% for single locus analysis in females. Combined power of discrimination was 0.99999999 and 0.999998764 for females and males, respectively. A priori probability detection of error expectancy in paternity cases (mean exclusion chance) was 0.99999463 (trios) and 0.999761591 (duos). Pairwise genetic distances (Fst) (Table 1) between the sample population of autochthonous Basques from Navarre indicate significant differences (p < 0.005, after Bonferroni correction) with other Iberian populations (except the Basque Country) and American populations, being furthest from the Pas Valley in the Iberian Peninsula and Rio de Janeiro in South America. An unrooted neighgbor-joining (NJ) tree (Fig. 2) was generated based on pairwise Fst-values which locates the autochthonous Basques from Navarre closest to the Basque Country population.
Fig. 2. Neighbor-joining tree based on pairwise genetic distances (Fst) for 10 X-STR markers. NA, Navarre; BC, Basque Country; PV, Pas Valley; CA, Cantabria; BAR, Barcelona; GA, Galicia; NP, North Portugal; CP, Central Portugal; MG, Mato Grosso do Sul; SP, Sa˜o Paulo; RJ, Rio de Janeiro; PA, Parana´; MI, Misiones; RN, Rio Negro; CO, Co´rdoba; AN, Antioquia; CR, Costa Rica. Autochthonous populations from the Northern Iberian Peninsula appear underlined.
4. Discussion The 10 X-STRs employed for the development of the allele frequency database of autochthonous Basques from Navarre show ideal characteristics for their use in forensic and paternity testing, such as absence of departure from Hardy–Weinberg equilibrium and linkage disequilibrium, high power of discrimination in both
females and males, and high mean exclusion chance values for duos and trios. The unrooted NJ tree generated based on pairwise genetic distances (Fst) shows a clear separation of the autochthonous Basque population from Navarre from Iberian populations, being closer to other sources of isolated autochthonous Basque
e148
M.J. Illescas et al. / Forensic Science International: Genetics 6 (2012) e146–e148
populations like the Basque Country. These results point to an evident substructuring of Basque populations suggested by Pe´rezMiranda et al. [1] and Garcı´a-Obrego´n et al. [12]. Although small pairwise genetic distances were determined when compared to other Iberian populations, significant p-values were obtained. Gusma˜o et al. [5] found no significant differences between Galicia and Portugal suggesting a mixed genetic profile that accounts for the differences reflected in these results when compared to an isolated population. In this sense, the case of the autochthonous Basques from Navarre is similar to the case of the Pas Valley [3]. Similarly, compared to Northern and Central Portugal, low pairwise genetic distances (Fst-value) were determined. However, the Fst-value correction is not higher than 1%. Furthermore, the largest Fst compared to non-Iberian populations was 2.6%, indicating that whenever a specific population reference database is not available, a 2.6% Fst-value correction should be used [13]. In the case of Argentina, the low Fst-values found for Buenos Aires might be due to the mixed genetic profile of European ancestry due to increasing immigrant population from Spain and Italy that the country has seen since mid-1800s [14] as qualified industrial, craftsmanship and rural workers specialized in cattle raising [15]. However, further population comparisons must be performed when allelic frequencies for other Spanish populations become available in order to determine the need to use a regional or specific national population reference database for forensic testing calculations involving X chromosome markers. 5. Conclusions The X-STR decaplex allelic database created for the autochthonous Basques from Navarre has notable impact in complex paternity and sibship diagnoses given its robustness and high power of discrimination and exclusion rendered by highly polymorphic loci. 6. Quality control This paper follows the guidelines for publication of population data requested by the journal [16] and the International Society for Forensic Genetics (ISFG), as well as abiding to ISFG recommendations on the analysis of DNA polymorphisms [17]. Conflict of interest The authors declare no competing interest in the content of this manuscript. Acknowledgements We would like to thank the donors who made this study possible. This project was supported by the Government of the Basque Country (Grupo Consolidado IT-424-07). Research activities at the University of the Basque Country were partially supported by Erasmus Mundus External
Cooperation Window through the EMUNDUS20 project and the Basque Country Government through the Department of Education, Universities and Research. Technical and human support provided by SGIker (UPV/EHU, MICINN, GV/EJ, ESF) and Progenika Biopharma S.A. is gratefully acknowledged. We also thank the Navarre Health Service and Nafarroako Batzokiak for their collaboration.
Appendix A. Supplementary data Supplementary data associated with this article can be found, in the online version, at doi:10.1016/j.fsigen.2012.02.014. References [1] A.M. Pe´rez-Miranda, M.A. Alfonso-Sa´nchez, A. Kalantar, S. Garcı´a-Obrego´n, M.M. de Pancorbo, J.A. Pen˜a, R.J. Herrera, Microsatellite data support subpopulation structuring among Basques, J. Hum. Genet. 50 (2005) 403–414. [2] F. Pe´rez-Lazaun, J. Calafell, E. Clarimo´n, E. Bosch, L. Mateu, L. Gusma˜o, A. Amorim, N. Benchemsi, J. Bertranpetit, Allele frequencies of 13 short tandem repeats in population samples from the Iberian Peninsula and Northern Africa, Int. J. Legal Med. 113 (2000) 208–214. [3] M.T. Zarrabeitia, F. Pinheiro, M.M. de Pancorbo, L. Caine´, S. Cardoso, L. Gusma˜o, J.A. Riancho, Analysis of 10 X-linked tetranucleotide markers in mixed and isolated populations, Forensic Sci. Int. Genet. 3 (2009) 63–66. [4] R. Szibor, M. Krawczak, S. Hering, J. Edlemann, E. Kuhlisch, D. Krause, Use of Xlinked markers for forensic purposes, Int. J. Legal Med. 117 (2003) 67–74. [5] L. Gusma˜o, P. Sa´nchez-Diz, C. Alves, I. Gomes, M.T. Zarrabeitia, M. Abovich, et al., A GEP-ISFG collaborative study on the optimization of an X-STR Decaplex: data on 15 Iberian and Latin American populations, Int. J. Legal Med. 123 (2009) 227–234. [6] B. Garcı´a, M. Crespillo, M. Paredes, J.L. Valverde, Population data for 10 Xchromosome STRs from north-east of Spain, Forensic Sci. Int. Genet. (2011), doi:10.1016/j.fsigen.2010.12.010. [7] Ley Orga´nica 15/1999 de Proteccio´n de Datos de Cara´cter personal BOE no. 29814, December 1999, pp. 43088–43099. www.boe.es/diario_boe/. [8] L. Excoffier, G. Laval, S. Schneider, Arlequin ver. 3.0: an integrated software package for population genetics data analysis, Evol. Bioinformatics Online 1 (2005) 47–50. [9] S.T. Kalinowski, TreeFit: a computer program for evaluating how well evolutionary trees fit genetic distance data, 2009. http://www.montana.edu/kalinowski. [10] R.D.M. Page, TreeView: an application to display phylogenetic trees on personal computers, Comput. Appl. Biosci. 12 (1996) 357–358. [11] D. Desmarais, Y. Zhong, R. Chakraborty, C. Perreault, L. Busque, Development of a highly polymorphic STR marker for identity testing purposes at the human androgen receptor gene (HUMARA), J. Forensic Sci. 43 (1998) 1046–1049. [12] S. Garcı´a-Obrego´n, M.A. Alfonso-Sa´nchez, A.M. Pe´rez-Miranda, M.M. de Pancrobo, J.A. Pen˜a, Polymorphic Alu insertions and the genetic structure of Iberian Basques, J. Hum. Genet. 52 (2007) 317–327. [13] K.L. Ayres, W.M. Powley, Calculating the exclusion probability and paternity index for X-chromosomal loci in the presence of substructure, Forensic Sci. Int. 149 (2005) 201–203. [14] V. Va´zquez de Prada, J.B. Amores, La emigracio´n de vascos y navarros al Nuevo Mundo y su repercusio´n en las comunidades de origen, in: La emigracio´n espan˜ola a Ultramar, 1492–1914, Tabapress, Espan˜a, 1991. [15] M.A. Salle Alonso, La emigracio´n espan˜ola en Ame´rica: historias y lecciones para el futuro, Editorial Fundacio´n Directa (2009). [16] A. Carracedo, J.M. Butler, L. Gusma˜o, W. Parson, L. Roewer, P.M. Schneider, Publication of population data for forensic purposes, Forensic Sci. Int. Genet. 4 (2010) 145–147. [17] W. Ba¨r, B. Brinkmann, B. Budowle, A. Carracedo, P. Gill, P. Lincoln, W. Mayr, B. Olaisen, DNA recommendations. Further report of the DNA Commission of the ISFH regarding the use of short tandem repeat systems, Int. J. Legal Med. 110 (1997) 175–176.