Expression and Methylation of Insulin-Like Growth Factor Binding Protein-1 Gene in Cord Blood of Intrauterine Growth Restricted Neonates.

Abstract

Objectives: To compare the insulin-like growth factor binding protein-1 (IGFBP-1) gene methylation and expression in the cord blood among intrauterine growth restricted (IUGR) and appropriate for gestational age (AGA) neonates and find their association with anthropometry at birth.

Methods: Cord blood samples from IUGR and AGA neonates were collected. Anthropometric measurements i.e., Weight, length and head circumference of the infants were measured. RT-PCR was performed to examine IGFBP-1 gene expression and DNA methylation analysis by bisulfite sequencing PCR. The results were analyzed by using Mann-Whitney U test and Pearson correlation.

Results: IUGR neonates had significantly lower anthropometry (weight, length and head circumference) measurements at birth compared to AGA neonates. Gene expression analysis showed significantly higher IGFBP-1 gene expressions among IUGR compared to AGA neonates and gene expression level correlated with anthropometric measurements. There was no difference in IGFBP-1 gene methylation rate between the two groups of neonates and no correlation was observed with anthropometry.

Conclusions: IGFBP-1 gene expression in cord blood was significantly higher among IUGR neonates and was associated with reduced birth weight, birth length and head circumference while the gene methylation was similar. This suggests involvement of multiple factors in occurrence of fetal growth restriction.