The polymorphism in insulin receptor substrate-1 gene and birth weight in neonates at term Polimorfizm genu substratu 1 receptora insuliny a masa ciała u noworodków urodzonych o czasie

Background: The mutation of the IRS-1 gene is one of the genetic risk factors which, it is speculated, is associated with insulin resistance or predisposition to type 2 diabetes. The aim of our study was to evaluate the association between the Gly972Arg polymorphism in the IRS-1 gene and birth weight in newborn children with adequate gestational age. Material and methods: 100 newborn children with adequate gestational age (38–42 weeks), whose mother had no disorders during pregnancy, were studied. Genomic DNA was extracted from umbilical cord blood leukocytes, and Gly972Arg polymorphism in the IRS-1 gene was genotyped using the PCR-based method. Results: Birth weight was significantly lower in the newborn with the IRS-1 Gly972Arg polymorphism compared with a control group (3161.75 ± 380.86 g vs. 3427.92 ± 468.86 g). Body length and head circumference at birth were also lower in the neonates with that polymorphism (54.38 ± 3.13 cm vs. 52.69 ± 2.91 cm, and 34.08 ± 1.47 vs. 33.63 ± 0.81, respectively). Conclusions: The results suggest that the Gly972Arg genotype is associated with lower birth weight, body length and head circumference in neonates with adequate gestational age. (Pol J Endocrinol 2008; 59 (3): 212–216)