NordicDB: a Nordic pool and portal for genome-wide control data.
A cost-efficient way to increase power in a genetic association study is to pool controls from different sources. The genotyping effort can then be directed to large case series. The Nordic Control database, NordicDB, has been set up as a unique resource in the Nordic area and the data are available for authorized users through the web portal (http://www.nordicdb.org). The current version of NordicDB pools together high-density genome-wide SNP information from ∼5000 controls originating from Finnish, Swedish and Danish studies and shows country-specific allele frequencies for SNP markers. The genetic homogeneity of the samples was investigated using multidimensional scaling (MDS) analysis and pairwise allele frequency differences between the studies. The plot of the first two MDS components showed excellent resemblance to the geographical placement of the samples, with a clear NW-SE gradient. We advise researchers to assess the impact of population structure when incorporating NordicDB controls in association studies. This harmonized Nordic database presents a unique genome-wide resource for future genetic association studies in the Nordic countries.
Leu
Monica
M
Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. monica.leu@ki.se
Humphreys
Keith
K
Surakka
Ida
I
Rehnberg
Emil
E
Muilu
Juha
J
Rosenström
Päivi
P
Almgren
Peter
P
Jääskeläinen
Juha
J
Lifton
Richard P
RP
Kyvik
Kirsten Ohm
KO
Kaprio
Jaakko
J
Pedersen
Nancy L
NL
Palotie
Aarno
A
Hall
Per
P
Grönberg
Henrik
H
Groop
Leif
L
Peltonen
Leena
L
Palmgren
Juni
J
Ripatti
Samuli
S
D016022:Case-Control Studies; D030541:Databases, Genetic; D005788:Gene Pool; D014644:Genetic Variation; D005828:Genetics, Population; D055106:Genome-Wide Association Study; D006801:Humans; D020407:Internet; D012537:Scandinavian and Nordic Countries