title: HLA-G(∗)01:05N null allele in Mayans (Guatemala) and Uros (Titikaka Lake, Peru): evolution and population genetics.
abstract: HLA-G molecules seem to have a protective effect for the semi-allogeneic fetus by mother immunosuppression. Also, pregnancy pathologies have been associated to HLA-G(∗)01:05N "null allele". In addition, other general regulatory immune functions have been associated to HLA-G in infections, tumors and autoimmunity. Thus, it is striking that HLA(∗)01:05N allele is maintained in a substantial frequency in certain human populations. In the present work, we have analysed HLA-G allele frequencies in Amerindian Mayans from Guatemala and in Uros from Titikaka Lake "totora" (reed) floating islands (Peru). No HLA-G(∗)01:05N has been found in both of these Amerindian populations. Further studies in Worldwide populations show that the highest HLA-G(∗)01:05 allele frequencies are found in Middle East; these findings have a bearing in future clinical/epidemiological studies in Amerindians. This would suggest that either this area was close to the "null" allele origin (as predicted by us) and/or some evolutive pressures are maintaining these high frequencies in Middle East. However, the fact that Cercopithecinae primate family (primates postulated as distant human ancestors) has also a MHC-G "null" allele in all individuals suggests that this allele may confer some advantage either at maternal/fetal interface or at other immune HLA-G function level (tumors, infections, autoimmunity). Human HLA-G(∗)01:05N may produce HLA-G isoforms, like Cercopithecinae monkeys may, which may suffice for function.
authors.affiliation: Department of Immunology, University Complutense, The Madrid Regional Blood Center, Madrid, Spain. aarnaiz@med.ucm.es
authors.forename: Antonio
authors.initials: A
authors.lastname: Arnaiz-Villena
authors.forename: Mercedes
authors.initials: M
authors.lastname: Enriquez-de-Salamanca
authors.forename: Cristina
authors.initials: C
authors.lastname: Areces
authors.forename: Javier
authors.initials: J
authors.lastname: Alonso-Rubio
authors.forename: Sedeka
authors.initials: S
authors.lastname: Abd-El-Fatah-Khalil
authors.forename: Mercedes
authors.initials: M
authors.lastname: Fernandez-Honrado
authors.forename: Diego
authors.initials: D
authors.lastname: Rey
mesh_terms: D000483:Alleles; D005075:Biological Evolution; D005260:Female; D005787:Gene Frequency; D005828:Genetics, Population; D006166:Guatemala; D059951:HLA-G Antigens / Q000235:genetics* / Q000276:immunology; D006801:Humans; D007199:Indians, South American / Q000235:genetics*; D008877:Middle East; D010568:Peru; D011110:Polymorphism, Genetic; D011247:Pregnancy; D044465:White People / Q000235:genetics*
chemical_list: D059951:HLA-G Antigens; C420206:HLA-G*01:05N antigen