Polymorphisms in the fetal progesterone receptor and a calcium-activated potassium channel isoform are associated with preterm birth in an Argentinian population

Objective:To investigate genetic etiologies of preterm birth (PTB) in Argentina through evaluation of single-nucleotide polymorphisms (SNPs) in candidate genes and population genetic admixture.Study Design:Genotyping was performed in 389 families. Maternal, paternal and fetal effects were studied separately. Mitochondrial DNA (mtDNA) was sequenced in 50 males and 50 females. Y-chromosome anthropological markers were evaluated in 50 males.Result:Fetal association with PTB was found in the progesterone receptor (PGR, rs1942836; P=0.004). Maternal association with PTB was found in small conductance calcium activated potassium channel isoform 3 (KCNN3, rs883319; P=0.01). Gestational age associated with PTB in PGR rs1942836 at 32-36 weeks (P=0.0004). MtDNA sequencing determined 88 individuals had Amerindian consistent haplogroups. Two individuals had Amerindian Y-chromosome consistent haplotypes.Conclusion:This study replicates single locus fetal associations with PTB in PGR, maternal association in KCNN3, and demonstrates possible effects for divergent racial admixture on PTB.