Common Polymorphisms of Growth Hormone: Growth Hormone Receptor Axis in Turkish Children with Short Stature

Abstract

Objective: A single-nucleotide polymorphism of the growth hormone 1 gene, GH1IVS4+90A>T (rs2665802), associated with short stature and a polymorphism of the growth hormone receptor gene, exon 3 deleted variant, associated with increased responsiveness to growth hormone have been reported previously. We aimed to investigate the frequency of both polymorphisms and their correlation to height in Turkish short children. Also, we aimed to evaluate the effect of exon 3 deleted variant on response to 1-year growth hormone therapy. Materials and Methods: Children with idiopathic isolated growth hormone deficiency (n = 39) and with idiopathic short stature (n = 10) and 50 control subjects were evaluated for anthropometric parameters, annual growth velocity, and annual height gain. Growth hormone receptor gene polymorphisms were analyzed via multiplex polymerase chain reaction; growth hormone 1 gene polymorphism was analyzed via polymerase chain reaction and single-strand conformation polymorphism techniques. Results: The frequency of genotypes carrying the A allele was not significantly higher in the idiopathic isolated growth hormone deficiency group than in the idiopathic short stature and control groups (P =.03 for each). The exon 3 deleted variant genotype was significantly lower in the idiopathic short stature group compared to the control group (P =.01). There was no effect of exon 3 deleted variant, on response to the first-year growth hormone therapy. Conclusion: In Turkish population, no correlation was found between the A allele of GH1IVS4+90A>T polymorphism and idiopathic isolated growth hormone deficiency and short stature, and a significant negative correlation was found between exon 3 deleted variant and idiopathic short stature and short stature. Exon 3 deleted variant has no effect on response to growth hormone treatment.