DMMC Course POPULATION GENETICS & SNP ANALYSIS

Durkan Lecture Theatre, Institute of Molecular Medicine, TCD, St James's Hospital

1610-1700 Wednesday 6 June 2007

Structure & Selection in the Irish Population
Prof Dan Bradley (Smurfit Institute of Genetics, Trinity College Dublin)

The earliest written account of Irish origins is the Book of Invasions which traces the Gaels (or Irish) back to a mythical king from northern Spain who conquered the prior inhabitants or Ireland and drove them underground. Coincidentally, recent genetic analyses (Y chromosome, mtDNA, classical polymorphisms) of Irish and other Atlantic Celtic populations show genetic affinities which point south to the Basque population in NW Spain/SW France rather than east toward continental Celtic homelands. The Basques speak an early, non-IndoEuropean language and their genetic distinctiveness is often interpreted as a legacy of an older, preagricultural stratum of Western European ancestry, which has been largely replaced elsewhere. The predominant pattern within Irish genetic diversity possibly also reflects a substantial ancestry rooted in the same Atlantic Mesolithic. However, this is one strand of ancestry and it is plain from genetic gradients within Ireland, which extend through the British Isles and beyond, that the island has substantial input from at least one other major European strand of ancestry, one possibly with an origin more strongly rooted in the Neolithic. A knowledge of underlying population structure is crucial for large scale SNP association studies.

References

McEvoy B, Bradley DG. (2006). Y-chromosomes and the extent of patrilineal ancestry in Irish surnames. Human Genetics 119, 212-219. PubMed Entry

Moore LT, McEvoy B, Cape E, Simms K, Bradley DG. (2006). A Y-chromosome signature of hegemony in gaelic Ireland. American Journal of Human Genetics 78, 334-338. PubMed Entry

McEvoy B, Richards M, Forster P, Bradley DG. (2004). The Longue Durée of genetic ancestry: multiple genetic marker systems and Celtic origins on the Atlantic facade of Europe. American Journal of Human Genetics 75, 693-702. PubMed Entry