title: PTX3 genetic variation and dizygotic twinning in the Gambia: could pleiotropy with innate immunity explain common dizygotic twinning in Africa?
abstract: Dizygotic (DZ) twinning has a genetic component and is common among sub-Saharan Africans; in The Gambia its frequency is up to 3% of live births. Variation in PTX3, encoding Pentraxin 3, a soluble pattern recognition receptor that plays an important role both in innate immunity and in female fertility, has been associated with resistance to Mycobacterium tuberculosis pulmonary disease and to Pseudomonas aeruginosa infection in cystic fibrosis patients. We tested whether PTX3 variants in Gambian women associate with DZ twinning, by genotyping five PTX3 single nucleotide polymorphisms (SNPs) in 130 sister pairs (96 full sibs and 34 half sibs) who had DZ twins. Two, three and five SNP haplotypes differed in frequency between twinning mothers and those without a history of twinning (from P = 0.006 to 3.03e-06 for two SNP and three SNP haplotypes, respectively). Twinning mothers and West African tuberculosis-controls from a previous study shared several frequent haplotypes. Most importantly, our data are consistent with an independently reported association of PTX3 and female fertility in a sample from Ghana. Taken together, these results indicate that selective pressure on PTX3 variants that affect the innate immune response to infectious agents, could also produce the observed high incidence of DZ twinning in Gambians.
authors: MRC Laboratories, Fajara, The Gambia, West Africa. sirugo.giorgio@fbfrm.it
authors: Giorgio
authors: G
authors: Sirugo
authors: Digna R Velez
authors: DR
authors: Edwards
authors: Kelli K
authors: KK
authors: Ryckman
authors: Cyrille
authors: C
authors: Bisseye
authors: Marquitta J
authors: MJ
authors: White
authors: Bunja
authors: B
authors: Kebbeh
authors: Gerard A J
authors: GA
authors: Morris
authors: Richard A
authors: RA
authors: Adegbola
authors: Alessandra
authors: A
authors: Tacconelli
authors: Irene M
authors: IM
authors: Predazzi
authors: Giuseppe
authors: G
authors: Novelli
authors: Fredrik O
authors: FO
authors: Vannberg
authors: Kunle
authors: K
authors: Odunsi
authors: Grier P
authors: GP
authors: Page
authors: Scott M
authors: SM
authors: Williams
mesh_terms: D000483:Alleles; D002097:C-Reactive Protein / Q000235:genetics*; D016022:Case-Control Studies; D002893:Chromosomes, Human, Pair 3; D005260:Female; D005714:Gambia; D005787:Gene Frequency; D023061:Gene Order; D006239:Haplotypes; D006801:Humans; D007113:Immunity, Innate / Q000235:genetics*; D015810:Linkage Disequilibrium; D020641:Polymorphism, Single Nucleotide; D000683:Serum Amyloid P-Component / Q000235:genetics*; D014429:Twins, Dizygotic / Q000235:genetics*; D000099153:Pentraxins
chemical_list: D002097:C-Reactive Protein; D000683:Serum Amyloid P-Component; D000099153:Pentraxins