title: African ancestry is a risk factor for asthma and high total IgE levels in African admixed populations.
abstract: Characterization of genetic admixture of populations in the Americas and the Caribbean is of interest for anthropological, epidemiological, and historical reasons. Asthma has a higher prevalence and is more severe in populations with a high African component. Association of African ancestry with asthma has been demonstrated. We estimated admixture proportions of samples from six trihybrid populations of African descent and determined the relationship between African ancestry and asthma and total serum IgE levels (tIgE). We genotyped 237 ancestry informative markers in asthmatics and nonasthmatic controls from Barbados (190/277), Jamaica (177/529), Brazil (40/220), Colombia (508/625), African Americans from New York (207/171), and African Americans from Baltimore/Washington, D.C. (625/757). We estimated individual ancestries and evaluated genetic stratification using Structure and principal component analysis. Association of African ancestry and asthma and tIgE was evaluated by regression analysis. Mean ± SD African ancestry ranged from 0.76 ± 0.10 among Barbadians to 0.33 ± 0.13 in Colombians. The European component varied from 0.14 ± 0.05 among Jamaicans and Barbadians to 0.26 ± 0.08 among Colombians. African ancestry was associated with risk for asthma in Colombians (odds ratio (OR) = 4.5, P = 0.001) Brazilians (OR = 136.5, P = 0.003), and African Americans of New York (OR: 4.7; P = 0.040). African ancestry was also associated with higher tIgE levels among Colombians (β = 1.3, P = 0.04), Barbadians (β = 3.8, P = 0.03), and Brazilians (β = 1.6, P = 0.03). Our findings indicate that African ancestry can account for, at least in part, the association between asthma and its associated trait, tIgE levels.
authors.affiliation: Division of Allergy and Clinical Immunology, Department of Medicine, Johns Hopkins University (JHU), Baltimore, MD, USA.
authors.forename: Candelaria
authors.initials: C
authors.lastname: Vergara
authors.forename: Tanda
authors.initials: T
authors.lastname: Murray
authors.forename: Nicholas
authors.initials: N
authors.lastname: Rafaels
authors.forename: Rachel
authors.initials: R
authors.lastname: Lewis
authors.forename: Monica
authors.initials: M
authors.lastname: Campbell
authors.forename: Cassandra
authors.initials: C
authors.lastname: Foster
authors.forename: Li
authors.initials: L
authors.lastname: Gao
authors.forename: Mezbah
authors.initials: M
authors.lastname: Faruque
authors.forename: Ricardo Riccio
authors.initials: RR
authors.lastname: Oliveira
authors.forename: Edgar
authors.initials: E
authors.lastname: Carvalho
authors.forename: Maria Ilma
authors.initials: MI
authors.lastname: Araujo
authors.forename: Alvaro A
authors.initials: AA
authors.lastname: Cruz
authors.forename: Harold
authors.initials: H
authors.lastname: Watson
authors.forename: Dilia
authors.initials: D
authors.lastname: Mercado
authors.forename: Jennifer
authors.initials: J
authors.lastname: Knight-Madden
authors.forename: Ingo
authors.initials: I
authors.lastname: Ruczinski
authors.forename: Georgia
authors.initials: G
authors.lastname: Dunston
authors.forename: Jean
authors.initials: J
authors.lastname: Ford
authors.forename: Luis
authors.initials: L
authors.lastname: Caraballo
authors.forename: Terri H
authors.initials: TH
authors.lastname: Beaty
authors.forename: Rasika A
authors.initials: RA
authors.lastname: Mathias
authors.forename: Kathleen C
authors.initials: KC
authors.lastname: Barnes
mesh_terms: D001741:Black or African American / Q000235:genetics; D000465:Algorithms; D001249:Asthma / Q000453:epidemiology / Q000208:ethnology* / Q000235:genetics*; D001460:Barbados; D044383:Black People / Q000235:genetics*; D001938:Brazil; D016022:Case-Control Studies; D003105:Colombia; D004219:District of Columbia; D020022:Genetic Predisposition to Disease; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood / Q000235:genetics*; D007563:Jamaica; D015233:Models, Statistical; D017720:Molecular Epidemiology; D009518:New York; D012307:Risk Factors; D044465:White People / Q000235:genetics
chemical_list: D007073:Immunoglobulin E
references.citation: J Allergy Clin Immunol. 1996 Jun;97(6):1393-401
references.pmid: 8648037
references.citation: Evol Bioinform Online. 2007 Feb 23;1:47-50
references.pmid: 19325852
references.citation: Am J Public Health. 2000 Dec;90(12):1923-5
references.pmid: 11111268
references.citation: Hum Genet. 2009 Jun;125(5-6):565-79
references.pmid: 19290544
references.citation: Int J Obes (Lond). 2011 Jan;35(1):60-5
references.pmid: 20877287
references.citation: PLoS One. 2011 Feb 28;6(2):e16522
references.pmid: 21387019
references.citation: Am J Respir Crit Care Med. 2006 Nov 15;174(10):1088-93
references.pmid: 16973984
references.citation: J Allergy Clin Immunol. 2010 Feb;125(2):336-346.e4
references.pmid: 19910028
references.citation: Trop Med Int Health. 2005 Jul;10(7):627-39
references.pmid: 15960701
references.citation: Clin Exp Allergy. 2012 Feb;42(2):265-74
references.pmid: 22093077
references.citation: Am Rev Respir Dis. 1993 Jul;148(1):10-8
references.pmid: 8317784
references.citation: MMWR Surveill Summ. 2007 Oct 19;56(8):1-54
references.pmid: 17947969
references.citation: J Allergy Clin Immunol. 1985 Jun;75(6):651-8
references.pmid: 4008794
references.citation: Am J Hum Genet. 1999 Jul;65(1):220-8
references.pmid: 10364535
references.citation: Am J Epidemiol. 2004 Dec 1;160(11):1033-8
references.pmid: 15561982
references.citation: J Infect Dis. 2008 Oct 15;198(8):1227-36
references.pmid: 18717640
references.citation: Pediatrics. 2005 May;115(5):1254-60
references.pmid: 15867032
references.citation: Pharmacogenomics. 2003 Jul;4(4):431-41
references.pmid: 12831322
references.citation: Hum Mutat. 2010 Feb;31(2):184-90
references.pmid: 19953531
references.citation: Paediatr Perinat Epidemiol. 1988 Apr;2(2):138-47
references.pmid: 3237494
references.citation: Annu Rev Genomics Hum Genet. 2010;11:65-89
references.pmid: 20594047
references.citation: Am J Hum Genet. 1993 Mar;52(3):506-16
references.pmid: 8447318
references.citation: Pediatrics. 2011 Oct;128(4):e821-9
references.pmid: 21890831
references.citation: Am J Phys Anthropol. 2010 May;142(1):49-66
references.pmid: 19918989
references.citation: N Engl J Med. 1989 Feb 2;320(5):271-7
references.pmid: 2911321
references.citation: Genet Med. 1999 Sep-Oct;1(6):267-71
references.pmid: 11258628
references.citation: Am J Respir Crit Care Med. 2006 Sep 1;174(5):508-13
references.pmid: 16763217
references.citation: Acad Emerg Med. 2004 Sep;11(9):944-50
references.pmid: 15347544
references.citation: PLoS One. 2011 Jan 31;6(1):e16513
references.pmid: 21304981
references.citation: Natl Health Stat Report. 2011 Jan 12;(32):1-14
references.pmid: 21355352
references.citation: Genet Epidemiol. 2005 Jul;29(1):76-86
references.pmid: 15918156
references.citation: Genet Epidemiol. 2010 Sep;34(6):561-8
references.pmid: 20717976
references.citation: Chest. 2001 Oct;120(4):1129-35
references.pmid: 11591549
references.citation: Proc Am Thorac Soc. 2007 Jan;4(1):58-68
references.pmid: 17202293
references.citation: Genetics. 1983 Nov;105(3):767-79
references.pmid: 17246175
references.citation: Ann Hum Genet. 2008 Jan;72(Pt 1):90-8
references.pmid: 17908263
references.citation: Lancet. 2003 Feb 15;361(9357):598-604
references.pmid: 12598158
references.citation: J Allergy Clin Immunol. 2001 Sep;108(3):357-62
references.pmid: 11544453
references.citation: Genomics. 1996 Oct 1;37(1):41-50
references.pmid: 8921368
references.citation: Diabetol Metab Syndr. 2010 Dec 07;2:68
references.pmid: 21134291
references.citation: Eur J Immunol. 1993 Jan;23(1):152-8
references.pmid: 8419165
references.citation: PLoS Genet. 2008 Mar 21;4(3):e1000037
references.pmid: 18369456
references.citation: Thorax. 2007 Sep;62(9):758-66
references.pmid: 17504817
references.citation: Int J Mol Med. 2005 Oct;16(4):573-80
references.pmid: 16142389
references.citation: Nat Rev Genet. 2004 Aug;5(8):598-609
references.pmid: 15266342
references.citation: Am J Respir Crit Care Med. 2008 Nov 15;178(10):1017-22
references.pmid: 18827265
references.citation: Braz J Med Biol Res. 2009 Oct;42(10):870-6
references.pmid: 19738982
references.citation: Hum Genet. 2008 Jun;123(5):455-68
references.pmid: 18401594
references.citation: PLoS Genet. 2006 Dec;2(12):e190
references.pmid: 17194218
references.citation: J Allergy Clin Immunol. 1988 Aug;82(2):179-89
references.pmid: 3403861
references.citation: Genes Immun. 2011 Jan;12(1):46-50
references.pmid: 20927126
references.citation: N Engl J Med. 2010 Jul 22;363(4):321-30
references.pmid: 20647190
references.citation: Ann Allergy Asthma Immunol. 2009 Aug;103(2):128-33
references.pmid: 19739425
references.citation: Genetics. 1995 Jan;139(1):457-62
references.pmid: 7705646
references.citation: J Allergy Clin Immunol. 2012 Sep;130(3):622-629.e9
references.pmid: 22607992
references.citation: PLoS One. 2012;7(1):e26807
references.pmid: 22235241
references.citation: PLoS Genet. 2009 May;5(5):e1000490
references.pmid: 19461885
references.citation: Am J Respir Crit Care Med. 1998 Nov;158(5 Pt 1):1487-92
references.pmid: 9817697
references.citation: Ann Allergy Asthma Immunol. 1997 Jan;78(1):21-6
references.pmid: 9012615
references.citation: Nature. 2007 Jun 7;447(7145):655-60
references.pmid: 17554299
references.citation: Am Rev Respir Dis. 1990 Sep;142(3):555-62
references.pmid: 2389907
references.citation: Am J Phys Anthropol. 2010 Sep;143(1):13-20
references.pmid: 20734436
references.citation: Proc Natl Acad Sci U S A. 1974 Sep;71(9):3588-92
references.pmid: 4139719