ABSTRACT
Objective To detect the relationship between the molecular defects and their phenotypes in children with growth hormone insensitivity syndrome (GHIS).Methods 21 patients defined as GHIS were enrolled in the study.4 candidate genes (GHR,IGFALS,JAK2,and STAT5B) were analyzed by genomic DNA sequence screening and clinical relevance analysis.Results The statistical descriptions of the patients were showed as an average height standard deviation (SDS)-4.33 ± 1.91 (-9.17 to-2.21),average serum peak values of GH (22.67 ±20.98) tg/L (11.33 to 104.21 μg/L),basal serum insulin-like growth factor-Ⅰ SDS-2.65 ± 0.53 (-3.57 to -1.79),insulin-like growth factor-binding protein 3 SDS-1.77 ± 1.64 (-4.13 to 0.96).Bone age of backward difference (chronological age-bone age) (43.10 ± 19.54) months (6 to 82 months).One of two children with severe growth failure and mid-face hypoplasia was found to a homozygote for G to A gene mutation in the intron 6 splice donor consensus sequences (IVS6 ds+ 1 G-A) in the GHR gene,causing its functional defect.3 cases with mild dwarf were found gene variations as novel finding:c.1097T＞C c.1098C＞T p.V366A pathogenic variant,c.1229C＞T p.S410L and nt1843707 A→G of 5' UTR region in the IGFALS gene.JAK2 and STAT5b genes mutations were not found.Conclusion Molecular pathology of GHIS is considered as involving the defects of GHR and its signal pathway.The mutation of intron 6 splice donor sequences in GHR gene has been reported which affect the function of GHR.The 3 novel type base variants in IGFALS gene,causing non severe dwarfism,might be suspected with pathogenic roles of GHIS.
ABSTRACT
PURPOSE: The aim was to investigate the clinical characteristics and responses to growth hormone (GH) therapy in children with attenuated growth who showed normal GH responses to GH stimulation tests (GHST). METHODS: The study included 39 patients with height velocity (HV) of less than 4 cm/yr and normal GHST results. Clinical characteristics of patients were analyzed retrospectively. RESULTS: Eleven were born as small for gestational age (SGA) and 28 as appropriate for age (AGA). In the SGA group, the standard deviation score (SDS) of age and height measured at their first visit was significantly low. Sixteen patients were treated with GH and six of 23 without GH therapy were followed for 1 year after GHST. The mean (range) of HV was 7.7 (4.9 to 11.1) cm/yr in patients with GH therapy and 3.7 (2.7 to 4.5) cm/yr in those without GH therapy, which was statistically significant (P or =3 (P=0.023). CONCLUSION: In children with growth failure and normal GHST, HV increases significantly by short-term GH therapy. The assessment of long-term effects of GH therapy is necessary. Moreover, further studies should be considered to evaluate the GH-IGF-I axis due to the possibility of GH insensitivity syndrome.