Article

European Journal of Human Genetics (2015) 23, 1549–1557; doi:10.1038/ejhg.2015.14; published online 18 February 2015

Y-chromosome diversity in Catalan surname samples: insights into surname origin and frequency

Neus Solé-Morata1, Jaume Bertranpetit1, David Comas1 and Francesc Calafell1

1Departament de Ciències Experimentals i de la Salut, Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Universitat Pompeu Fabra, CEXS-UPF-PRBB, Barcelona, Catalonia, Spain

Correspondence: Professor F Calafell, Departament de Ciències Experimentals i de la Salut, Institute of Evolutionary Biology (CSIC-Universitat Pompeu Fabra), Universitat Pompeu Fabra, CEXS-UPF-PRBB, Doctor Aiguader 88, Barcelona, Catalonia 08005, Spain. Tel: +34 93 316 08 42; Fax: +34 93 316 09 01; E-mail: francesc.calafell@upf.edu

Received 16 September 2014; Revised 26 November 2014; Accepted 13 January 2015
Advance online publication 18 February 2015

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Abstract

The biological behavior of the Y chromosome, which is paternally inherited, implies that males sharing the same surname may also share a similar Y chromosome. However, socio-cultural factors, such as polyphyletism, non-paternity, adoption, or matrilineal surname transmission, may prevent the joint transmission of the surname and the Y chromosome. By genotyping 17 Y-STRs and 68 SNPs in ~2500 male samples that each carried one of the 50 selected Catalan surnames, we could determine sets of descendants of a common ancestor, the population of origin of the common ancestor, and the date when such a common ancestor lived. Haplotype diversity was positively correlated with surname frequency, that is, rarer surnames showed the strongest signals of coancestry. Introgression rates of Y chromosomes into a surname by non-paternity, adoption, and transmission of the maternal surname were estimated at 1.5−2.6% per generation, with some local variation. Average ages for the founders of the surnames were estimated at ~500 years, suggesting a delay between the origin of surnames (twelfth and thirteenth centuries) and the systematization of their paternal transmission. We have found that, in general, a foreign etymology for a surname does not often result in a non-indigenous origin of surname founders; however, bearers of some surnames with an Arabic etymology show an excess of North African haplotypes. Finally, we estimate that surname prediction from a Y-chromosome haplotype, which may have interesting forensic applications, has a ~60% sensitivity but a 17% false discovery rate.