Genome-wide association study of ancestry-specific TB risk in the South African Coloured population.
The worldwide burden of tuberculosis (TB) remains an enormous problem, and is particularly severe in the admixed South African Coloured (SAC) population residing in the Western Cape. Despite evidence from twin studies suggesting a strong genetic component to TB resistance, only a few loci have been identified to date. In this work, we conduct a genome-wide association study (GWAS), meta-analysis and trans-ethnic fine mapping to attempt the replication of previously identified TB susceptibility loci. Our GWAS results confirm the WT1 chr11 susceptibility locus (rs2057178: odds ratio = 0.62, P = 2.71e(-06)) previously identified by Thye et al., but fail to replicate previously identified polymorphisms in the TLR8 gene and locus 18q11.2. Our study demonstrates that the genetic contribution to TB risk varies between continental populations, and illustrates the value of including admixed populations in studies of TB risk and other complex phenotypes. Our evaluation of local ancestry based on the real and simulated data demonstrates that case-only admixture mapping is currently impractical in multi-way admixed populations, such as the SAC, due to spurious deviations in average local ancestry generated by current local ancestry inference methods. This study provides insights into identifying disease genes and ancestry-specific disease risk in multi-way admixed populations.
Department of Clinical Laboratory Sciences, Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Cape Town, South Africa.
Emile R
ER
Chimusa
Noah
N
Zaitlen
Michelle
M
Daya
Marlo
M
Möller
Paul D
PD
van Helden
Nicola J
NJ
Mulder
Alkes L
AL
Price
Eileen G
EG
Hoal
D044383:Black People / Q000235:genetics*; D016022:Case-Control Studies; D056445:Cytoplasmic Dyneins / Q000235:genetics; D005260:Female; D020022:Genetic Predisposition to Disease; D005828:Genetics, Population; D055106:Genome-Wide Association Study; D060148:HapMap Project; D006801:Humans; D008297:Male; D020641:Polymorphism, Single Nucleotide; D013019:South Africa; D014376:Tuberculosis / Q000235:genetics*; D025721:WT1 Proteins / Q000235:genetics; D044465:White People / Q000235:genetics
C099883:DYNC2H1 protein, human; D025721:WT1 Proteins; C583751:WT1 protein, human; D056445:Cytoplasmic Dyneins