TY - JOUR
T1 - High heritability but uncertain mode of inheritance for total serum IgE level and Schistosoma mansoni infection intensity in a schistosomiasis-endemic Brazilian population
AU - Grant, Audrey V.
AU - Araujo, Maria Ilma
AU - Ponte, Eduardo Vieira
AU - Oliveira, Ricardo Riccio
AU - Cruz, Alvaro A.
AU - Barnes, Kathleen C.
AU - Beaty, Terri H.
N1 - Funding Information:
Financial support: Glaxo-Smith-Kline (project WE445 entitled “Immunogenetics of Schistosomiasis and Asthma” to A.V.G., E.V.P., and R.R.O.); National Institutes of Health (grant AI050024); Mary Beryl Patch Turnbull Scholar Program (support to K.C.B.). Some of the results in this paper were obtained by using the Statistical Analysis for Genetic Epidemiology (S.A.G.E.) package, which is supported by a US Public Health Service Resource Grant (RR03655) from the National Center for Research Resources.
PY - 2008/10/15
Y1 - 2008/10/15
N2 - Background. Evidence of genetic control for total serum IgE (tIgE) level has been reported in multiple populations, although populations with substantial exposure to helminths have yielded lower estimates of heritability, despite evidence suggesting that genes also control a significant portion of the variation in the number of Schistosoma mansoni eggs per gram of fecal matter. Methods. By use of a whole-population ascertainment scheme, 822 individuals were enrolled from a schistosomiasis-endemic area in Conde, Bahia, in Brazil. Heritability was estimated by using an additive polygenic model, and segregation analysis was performed for 2 quantitative traits, tIgE level and egg count. Results. After adjusting for nongenetic covariates, the heritability of log-transformed tIgE level and log-transformed egg count was estimated at 60% and 31%, respectively. No evidence for a single major gene controlling tIgE level or egg count was observed in segregation analysis for 781 individuals and 403 individuals, respectively, in 318 families, however, which suggests complex biological control. Conclusions. The high heritability of tIgE level indicates that genetic factors are likely to control tIgE level even in the presence of helminthic infection. Substantial heritability for the burden of S. mansoni infection was confirmed in these Brazilian families. Further genetic studies will be needed to dissect the specific genetic factors that underlie these traits.
AB - Background. Evidence of genetic control for total serum IgE (tIgE) level has been reported in multiple populations, although populations with substantial exposure to helminths have yielded lower estimates of heritability, despite evidence suggesting that genes also control a significant portion of the variation in the number of Schistosoma mansoni eggs per gram of fecal matter. Methods. By use of a whole-population ascertainment scheme, 822 individuals were enrolled from a schistosomiasis-endemic area in Conde, Bahia, in Brazil. Heritability was estimated by using an additive polygenic model, and segregation analysis was performed for 2 quantitative traits, tIgE level and egg count. Results. After adjusting for nongenetic covariates, the heritability of log-transformed tIgE level and log-transformed egg count was estimated at 60% and 31%, respectively. No evidence for a single major gene controlling tIgE level or egg count was observed in segregation analysis for 781 individuals and 403 individuals, respectively, in 318 families, however, which suggests complex biological control. Conclusions. The high heritability of tIgE level indicates that genetic factors are likely to control tIgE level even in the presence of helminthic infection. Substantial heritability for the burden of S. mansoni infection was confirmed in these Brazilian families. Further genetic studies will be needed to dissect the specific genetic factors that underlie these traits.
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U2 - 10.1086/591946
DO - 10.1086/591946
M3 - Article
C2 - 18717640
AN - SCOPUS:54749126920
SN - 0022-1899
VL - 198
SP - 1227
EP - 1236
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
IS - 8
ER -