Abstract:
【Abstract】 Objective To analyze the association between the genetic polymorphisms of rs10833
locus of interleukin (IL)-15 gene and genetic susceptibility to spontaneous preterm birth (SPTB) and
to obtain susceptibility genes and single nucleotide polymorphisms (SNPs) in Chinese population.
Methods From January 2009 to September 2014, among the newborns hospitalized in the premature
intensive care unit of Bayi Children's Hospital, the Seventh Medical Center of PLA General Hospital, Han
nationality newborns from Beijing and surrounding areas who were not genetically related were selected
for the study. In the case group, the newborns with gestational age less than 37 weeks, singleton pregnancy
and SPTB were included. In the control group, the newborns with gestational age greater than 37 weeks and
singleton pregnancy were included, and the pregnant women had no history of SPTB or preterm rupture of
membranes (PPROM). Neonatal blood samples were collected and SNP typing of rs10833 polymorphism of
IL-15 gene was carried out by using Sequenom MassARRAY?SNP technology. The genotype frequency and
allele of each SNP locus were expressed by frequency (percentage), and were analyzed in fifive genetic models
of codominance, dominance, superdominance, additiveness and recessiveness. The statistical analysis were
performed by χ2 test and Logistic regression. Results 718 cases in the case group were further divided into
three subgroups (59 cases in the super preterm group, 186 cases in the extremely preterm group and 473 cases
in the mild preterm group). The control group was 641 cases. There was no signifificant difference between the
case group and the three subgroups compared with the control group in the distribution frequency of alleles G,
A and the proportion of GG, GA, AA genotypes (P>0.05). Logistic regression analysis showed that rs10833
locus of IL-15 gene was not related to the genetic susceptibility of SPTB, and was not related to the genetic
susceptibility of super preterm birth, extremely preterm birth and mild preterm birth (P>0.05). The patients
of case group were further divided into two groups: PPROM group (197 cases) and without PPROM group
(521 cases). The distribution frequency of A allele in PPROM group was lower than that in the control group
(χ2
=5.660, P=0.020), but there was no signifificant difference in the proportion of GG, GA and AA genotypes
in two groups (χ2
=5.510, P=0.060). Logistic regression analysis showed that the A allele of IL-15 rs10833
was the protective allele of PPROM and had dose effect, and GA genotype was the protective genotype of
PPROM. The distribution frequency of A allele in the group without PPROM was higher than that in the
control group (χ2
=4.310, P=0.038), but there was no signifificant statistical difference in the proportion of GG,
GA, AA genotypes in two groups (χ2
=5.340，P=0.070). Logistic regression analysis showed that the A allele
of IL-15 rs10833 was a risk allele without PPROM and had dose effect. The A allele (GA + AA genotype) was a risk genotype of SPTB without PPROM. Conclusion The A allele and GA genotype of rs10833 polymorphism of IL-15 gene can reduce the risk of PPROM.
2020, Vol. 8 
