Relationship between initial treatment effect of recombinant human growth hormone and exon 3 polymorphism of growth hormone receptor in Chinese children with growth hormone deficiency

The aim of this study is to investigate the frequency distribution of exon 3 deleted (d3-GHR) genetic polymorphism of growth hormone receptor (GHR) in growth hormone deficient (GHD) Chinese children and to explore the correlation between the growth promoting effects of recombinant human growth hormone (rhGH) and exon 3 genetic polymorphism of GHR in GHD children. In this study, 111 GHD (excluded small for gestational age) children were treated with rhGH (0.20 mg/kg/week) for six months. The body height (Ht), body weight, bone age (BA) and growth velocity (GV) were measured before and after six months of treatment. The d3-GHR and full length GHR (fl-GHR) were analyzed to detect the frequency distribution of two isoforms and their influence on growth promoting effect of rhGH. The results indicated that the frequencies of fl/fl, fl/d3 and d3/d3 GHR genotypes were 67.6%, 18.9% and 13.5%. After six months of GH therapy, there were significant differences of Delta GV (Delta GV: 10.77 +/- 3.40 cm/year vs 12.18 +/- 3.08 cm/year) (P < 0.05) and Delta Ht (.Delta t: 5.38 +/- 1.70 cm vs 6.09 +/- 1.54 cm) (P < 0.05) were found among GHD children with different genotypes (fl/fl vs fl/d3 and d3/d3). In conclusion, the frequency distribution of three GHR genotypes in 111 Chinese GHD children was different from that reported in Caucasian, indicating the existence of ethnic difference of exon 3 GHR polymorphism. There was a closely relationship between GHR genotypes and growth-promoting effect of rhGH in Chinese GHD children.