[GHRd3 polymorphism of growth hormone receptor gen in peruvian children with idiopathic short stature]

Area of Science:

• Genetics
• Molecular Biology
• Pediatric Endocrinology

Background:

• Idiopathic short stature (ISS) affects children's growth.
• The growth hormone receptor (GHR) gene plays a crucial role in growth.
• A specific GHR polymorphism, GHRd3, may influence response to growth hormone therapy.

Purpose of the Study:

• To standardize a molecular assay for detecting the GHRd3 polymorphism.
• To determine the frequency of GHRd3 in Peruvian children with ISS.
• To assess the utility of GHRd3 genotyping in guiding treatment decisions.

Main Methods:

• Developed and optimized a Polymerase Chain Reaction (PCR) assay using specific primers (G1, G2, G3) to amplify exon 3 of the GHR gene.
• Optimized PCR conditions including annealing temperature (67°C) and magnesium concentration.
• Analyzed peripheral blood samples from 64 Peruvian children diagnosed with ISS.

Main Results:

• The PCR assay demonstrated high specificity at 67°C.
• Genotyping revealed GHRfl homozygous in 67% of patients, heterozygous in 28%, and GHRd3 homozygous in 5%.
• No significant differences were observed based on magnesium concentration tests.

Conclusions:

• The developed molecular assay is effective for determining GHR genotypes in children with ISS.
• Only 5% of the studied population possessed the GHRd3 homozygous genotype, potentially indicating a better response to recombinant human growth hormone (rhGH) therapy.
• Molecular genotyping may aid clinicians in deciding whether to initiate rhGH treatment.