Two quantitative trait loci influence whipworm (Trichuris trichiura) infection in a Nepalese population.
BACKGROUND
Whipworm (Trichuris trichiura) infection is a soil-transmitted helminth infection that affects >1 billion people. It is a serious public health problem in many developing countries and can result in deficits in growth and cognitive development. In a follow-up study of significant heritability for whipworm infection, we conducted the first genome scan for quantitative trait loci (QTL) influencing the heritability of susceptibility to this important parasitic disease.


METHODS
Whipworm egg counts were determined for 1,253 members of the Jirel population of eastern Nepal. All individuals in the study sample belonged to a single pedigree including >26,000 pairs of relatives that are informative for genetic analysis.


RESULTS
Linkage analysis of genome scan data generated for the pedigree provided unambiguous evidence for 2 QTL influencing susceptibility to whipworm infection, one located on chromosome 9 (logarithm of the odds ratio [LOD] score, 3.35; genomewide P = .0138) and the other located on chromosome 18 (LOD score, 3.29; genomewide P = .0159). There was also suggestive evidence that 2 loci located on chromosomes 12 and 13 influenced whipworm infection.


CONCLUSIONS
The results of this first genome scan for T. trichiura egg counts provides new information on the determinants of genetic predisposition to whipworm infection.
Williams-Blangero
Sarah
S
Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, Texas 78245-0549, USA. sarah@sfbrgenetics.org
Vandeberg
John L
JL
Subedi
Janardan
J
Jha
Bharat
B
Dyer
Tom D
TD
Blangero
John
J
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D002648:Child; D002675:Child, Preschool; D002874:Chromosome Mapping; D005243:Feces / Q000469:parasitology; D005260:Female; D005767:Gastrointestinal Diseases / Q000453:epidemiology / Q000235:genetics* / Q000469:parasitology*; D020022:Genetic Predisposition to Disease; D015894:Genome, Human; D006801:Humans; D008126:Lod Score; D008297:Male; D008875:Middle Aged; D009390:Nepal / Q000453:epidemiology; D010270:Parasite Egg Count; D015995:Prevalence; D040641:Quantitative Trait Loci; D014257:Trichuriasis / Q000453:epidemiology / Q000235:genetics* / Q000469:parasitology; D014258:Trichuris / Q000254:growth & development*