ABSTRACT
Objective:To investigate the relationship between the polymorphisms of two SNP loci (rs901823 and rs3736228) in the low density lipoprotein receptor-associated protein 5 (LRP5) gene and glucocorticoids-induced osteoporosis (GIOP) in children.Methods:87 children with GIOP who were treated in Beijing Aiyuhua Women’s and Children’s Hospital and Beijing Children’s Hospital affiliated to Capital Medical University from Jan. 2015 to Dec. 2020 were selected as the research objects, and 100 children with normal bone mass who were treated with corticosteroids in this hospital during the same period were enrolled as the control group. Capillary electrophoresis and fragment analysis (SNaPshot) technology were used to genotype SNP sites rs901823 (T>C) and rs3736228 (C>T) ; Quantitative real-time fluorescence quantitative polymerase chain reaction detection method was employed to determine the relative mRNA of LPR5 gene The amount of expression.Results:For the rs901823 locus of the LRP5 gene, the TT, TC, and CC genotype distribution differences between the GIOP group and the control group were statistically significant ( χ2=14.176, P=0.001) . Compared with the TT genotype, carriers of the TC and CC genotypes had a higher risk of GIOP, with OR values of 3.022 (1.189-6.387) and 5.483 (1.452-20.883) ; For academic significance, OR values were 3.412 (1.795-6.587) and 4.352 (1.215-15.982) . For the rs3736228 locus, the distribution of CC, CT, TT genotypes between the GIOP group and the control group was significantly different ( χ2=9.597, P=0.008) . Compared with CC carriers, CT genotype carriers had a significantly increased risk of GIOP, with an OR value of 5.125 (1.721-16.241) . The result of a dominant model was statistically significant, with an OR value of 4.165 (1.335-14.652) , while for TT there was no statistically significant difference between the carrier and the CC genotype ( P=0.512) , and the results of the recessive model also showed no significant statistical significance ( P=0.887) . There was a statistically significant difference in the frequency distribution of T and C alleles at rs901823 between the GIOP group and the control group ( χ2=17.298, P<0.001) , and the difference in the frequency distribution of C and T alleles at rs3736228 was also statistically significant ( χ2=9.356, P=0.002) . The relative expression level of LRP5 gene mRNA in children with GIOP was 1.34±0.26, which was significantly lower than the expression level of LRP5 gene mRNA in children in the control group of 3.06±0.42 ( t=8.248, P<0.001) . Among children with GIOP, the relative expression of LRP5 gene mRNA in patients with rs901823 locus TT, TC, and CC genotypes was statistically significant ( P<0.001) ; the differences in rs901823 locus CC, CT, TT genotype patients were significant. Pairwise comparison of the relative expression of LRP5 gene mRNA showed that there was no significant difference between the TT group and the CT group ( P>0.05) , but the expression of the CC group was significantly higher than that of the CT group and the TT group ( P<0.05) . Conclusion:The rs901823 and rs3736228 polymorphisms of LRP5 gene are correlated with the occurrence of GIOP and can be used as genetic markers for predicting GIOP in children.