No effect of the IGF-1 gene rs35767 and rs17032362 polymorphisms in the etiology of idiopathic short stature

Abstract

Idiopathic short stature (ISS) refers to pathophysiologically wide and heterogeneous range of disorders, which are considered to involve defects in growth hormone (GH) insulin like growth factor-1 (IGF-1) axis. This study was designed to evaluate GH- IGF-1 axis and investigate IGF-1 gene polymorphisms in ISS.108 patients with a mean age of 11.7±3.6 years constituted the study group, while 108 age and gender matched children with normal stature constituted the control group. Serum IGF-1 and insulin-like growth factor binding protein-3 (IGFBP-3) levels and two polymorphisms in IGF-1 gene (rs35767, rs17032362) were investigated.While mean IGF-1 SDS value was lower in study group (p=0.002), no difference was detected between mean IGFBP-3 SDS values. The IGF-1 gene rs35767 polymorphism genotype distribution did not exhibit a statistical difference between study (7.1% wild type, 29.6% heterozygous, 63.3% homozygous) and control groups (3.8% wild type, 39.6% heterozygous, 56.6% homozygous). IGF-1 gene rs17032362 polymorphism genotype distribution was not significantly different either between study (94.8% wild type, 5.2% heterozygous, 0% homozygous) and control groups (97.2% wild type, 2.8% heterozygous, 0% homozygous). Comparing the cases with wild type, homozygous and heterozygous carriers for both polymorphisms with respect to height, weight, BMI, IGF-1 and IGFBP-3 SDS values, no significant difference was detected.IGF-1 SDS levels of patients with ISS were significantly lower compared to control group. There was no difference between IGFBP-3 SDS levels. No effect of IGF-1 gene rs35767 and rs17032362 polymorphisms on stature, IGF-1 and IGFBP-3 levels could be demonstrated.