title: An assessment of the Irish population for large-scale genetic mapping studies involving epilepsy and other complex diseases.
abstract: The recent completion of the International HapMap Project has rapidly advanced our understanding of linkage disequilibrium (LD) in the human genome. Today, tagging SNPs (tSNPs) can be quickly and easily selected and consequently HapMap data are regularly applied to both small- and large-scale genetic mapping studies. However, to correctly interpret the application of HapMap-derived tSNPs in a genetic mapping study, an understanding of how well HapMap data represents LD in the study population is critical. The Irish population had not previously been characterised in this way. Here, we do so using a set of 4424 SNPs selected from 279 candidate genes for epilepsy genotyped across 1118 healthy individuals from the Irish, British, Finnish and Australian populations. By considering the Irish population alongside surrounding European populations, our results confirm that the HapMap European-derived population accurately estimates patterning of LD in European descent populations. The Irish population appears notably well matched to the European HapMap population, and is markedly similar to the neighbouring British population. Although we were unable to detect significant substructure within the Irish population (a favourable result for genetic mapping), methods for controlling stratification should always be incorporated. This analysis therefore confirms that the genetic architecture of the Irish population is well suited to the study of complex traits and that tSNPs selected using the HapMap data can be confidently applied to the Irish population.
authors.affiliation: Neuropsychiatric Genetics Research Group, Department of Psychiatry, Trinity College Dublin, Ireland.
authors.forename: Colm T
authors.initials: CT
authors.lastname: O'Dushlaine
authors.forename: Ciara
authors.initials: C
authors.lastname: Dolan
authors.forename: Michael E
authors.initials: ME
authors.lastname: Weale
authors.forename: Alice
authors.initials: A
authors.lastname: Stanton
authors.forename: David T
authors.initials: DT
authors.lastname: Croke
authors.forename: Reetta
authors.initials: R
authors.lastname: Kalviainen
authors.forename: Kai
authors.initials: K
authors.lastname: Eriksson
authors.forename: Anne-Mari
authors.initials: AM
authors.lastname: Kantanen
authors.forename: Rachel A
authors.initials: RA
authors.lastname: Gibson
authors.forename: David
authors.initials: D
authors.lastname: Hosford
authors.forename: Sanjay M
authors.initials: SM
authors.lastname: Sisodiya
authors.forename: Michael
authors.initials: M
authors.lastname: Gill
authors.forename: Aiden P
authors.initials: AP
authors.lastname: Corvin
authors.forename: Derek W
authors.initials: DW
authors.lastname: Morris
authors.forename: Norman
authors.initials: N
authors.lastname: Delanty
authors.forename: Gianpiero L
authors.initials: GL
authors.lastname: Cavalleri
mesh_terms: D002874:Chromosome Mapping; D004827:Epilepsy / Q000235:genetics*; D005787:Gene Frequency; D005828:Genetics, Population; D006239:Haplotypes; D006801:Humans; D007494:Ireland; D015810:Linkage Disequilibrium; D020412:Multifactorial Inheritance / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide