Heritability of malaria in Africa.

While many individual genes have been identified that confer protection against malaria, the overall impact of host genetics on malarial risk remains unknown.We have used pedigree-based genetic variance component analysis to determine the relative contributions of genetic and other factors to the va...

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Main Authors: Margaret J Mackinnon, Tabitha W Mwangi, Robert W Snow, Kevin Marsh, Thomas N Williams
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2005-12-01
Series:PLoS Medicine
Online Access:http://europepmc.org/articles/PMC1277928?pdf=render
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author Margaret J Mackinnon
Tabitha W Mwangi
Robert W Snow
Kevin Marsh
Thomas N Williams
author_facet Margaret J Mackinnon
Tabitha W Mwangi
Robert W Snow
Kevin Marsh
Thomas N Williams
author_sort Margaret J Mackinnon
collection DOAJ
description While many individual genes have been identified that confer protection against malaria, the overall impact of host genetics on malarial risk remains unknown.We have used pedigree-based genetic variance component analysis to determine the relative contributions of genetic and other factors to the variability in incidence of malaria and other infectious diseases in two cohorts of children living on the coast of Kenya. In the first, we monitored the incidence of mild clinical malaria and other febrile diseases through active surveillance of 640 children 10 y old or younger, living in 77 different households for an average of 2.7 y. In the second, we recorded hospital admissions with malaria and other infectious diseases in a birth cohort of 2,914 children for an average of 4.1 y. Mean annual incidence rates for mild and hospital-admitted malaria were 1.6 and 0.054 episodes per person per year, respectively. Twenty-four percent and 25% of the total variation in these outcomes was explained by additively acting host genes, and household explained a further 29% and 14%, respectively. The haemoglobin S gene explained only 2% of the total variation. For nonmalarial infections, additive genetics explained 39% and 13% of the variability in fevers and hospital-admitted infections, while household explained a further 9% and 30%, respectively.Genetic and unidentified household factors each accounted for around one quarter of the total variability in malaria incidence in our study population. The genetic effect was well beyond that explained by the anticipated effects of the haemoglobinopathies alone, suggesting the existence of many protective genes, each individually resulting in small population effects. While studying these genes may well provide insights into pathogenesis and resistance in human malaria, identifying and tackling the household effects must be the more efficient route to reducing the burden of disease in malaria-endemic areas.
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spelling doaj.art-287e1d2e0c7740e1b368164465893d0f2022-12-21T20:28:37ZengPublic Library of Science (PLoS)PLoS Medicine1549-12771549-16762005-12-01212e34010.1371/journal.pmed.0020340Heritability of malaria in Africa.Margaret J MackinnonTabitha W MwangiRobert W SnowKevin MarshThomas N WilliamsWhile many individual genes have been identified that confer protection against malaria, the overall impact of host genetics on malarial risk remains unknown.We have used pedigree-based genetic variance component analysis to determine the relative contributions of genetic and other factors to the variability in incidence of malaria and other infectious diseases in two cohorts of children living on the coast of Kenya. In the first, we monitored the incidence of mild clinical malaria and other febrile diseases through active surveillance of 640 children 10 y old or younger, living in 77 different households for an average of 2.7 y. In the second, we recorded hospital admissions with malaria and other infectious diseases in a birth cohort of 2,914 children for an average of 4.1 y. Mean annual incidence rates for mild and hospital-admitted malaria were 1.6 and 0.054 episodes per person per year, respectively. Twenty-four percent and 25% of the total variation in these outcomes was explained by additively acting host genes, and household explained a further 29% and 14%, respectively. The haemoglobin S gene explained only 2% of the total variation. For nonmalarial infections, additive genetics explained 39% and 13% of the variability in fevers and hospital-admitted infections, while household explained a further 9% and 30%, respectively.Genetic and unidentified household factors each accounted for around one quarter of the total variability in malaria incidence in our study population. The genetic effect was well beyond that explained by the anticipated effects of the haemoglobinopathies alone, suggesting the existence of many protective genes, each individually resulting in small population effects. While studying these genes may well provide insights into pathogenesis and resistance in human malaria, identifying and tackling the household effects must be the more efficient route to reducing the burden of disease in malaria-endemic areas.http://europepmc.org/articles/PMC1277928?pdf=render
spellingShingle Margaret J Mackinnon
Tabitha W Mwangi
Robert W Snow
Kevin Marsh
Thomas N Williams
Heritability of malaria in Africa.
PLoS Medicine
title Heritability of malaria in Africa.
title_full Heritability of malaria in Africa.
title_fullStr Heritability of malaria in Africa.
title_full_unstemmed Heritability of malaria in Africa.
title_short Heritability of malaria in Africa.
title_sort heritability of malaria in africa
url http://europepmc.org/articles/PMC1277928?pdf=render
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AT thomasnwilliams heritabilityofmalariainafrica