Background/Aims: The objective of this study was to evaluate the efficacy of recombinant human growth hormone (rhGH) therapy and the influence of genotype on the response to rhGH therapy in children with Noonan syndrome (NS). Methods: 14 male and 4 female subjects with NS with short stature, whose height was <3rd percentile, were included. The rhGH was subcutaneously administered at a dose of 66 µg/kg/day. Mutations in the PTPN11 gene were identified in 10 subjects (55.6%). Mutations in the SOS1 (2 children, 11.1%), MEK1 (1 child, 5.6%) and KRAS (1 child, 5.6%) genes were also found. Results: Height SDS increased from –2.8 ± 0.9 at the start of rhGH therapy to –2.0 ± 0.9 12 months later (p < 0.001). Height velocity increased from 5.0 ± 0.9 cm/year in the year before treatment to 8.9 ± 1.6 during treatment (p < 0.001). Changes in height SDS, height velocity, and serum IGF-1 level did not differ significantly between those children with or without PTPN11 mutations. Conclusion: The rhGH therapy significantly improved the growth velocity and increased the serum IGF-1 level. Long-term correlation between genotype and rhGH therapy responsiveness needs to be addressed in a large population.

Steroid 21-hydroxylase deficiency is caused by inactivating mutations in the CYP21A2 gene. This paper reports on the mutation spectrum and the genotype-phenotype correlation of 21-hydroxylase deficiency. 72 unrelated patients with congenital adrenal hyperplasia (CAH) were included. Molecular analysis of CYP21A2 was performed, via the multiplex ligation-dependent probe amplification (MLPA) analysis and sequence-specific differenzial PCR amplification of the CYP21A2 and CYP21A1P genes, using 4 pair-wise sequence-specific primers, followed by sequencing of the entire CYP21A2 gene. Large gene deletions were identified in 45 (31.3%) of the 144 unrelated CAH alleles, whereas the most frequent point mutations were intron 2 splice mutations (c.293-13A>G) (41/144, 28.5%). The MLPA analysis successfully identified 23 of 72 patients (31.9%) with single copy deletion in CYP21A2. This paper describes a rapid and accurate method for the molecular diagnosis of 21-hydroxylase deficiency, which relies on the identification of point mutations and structural rearrangements within the CYP21A2 gene.

This study was undertaken to identify growth hormone (GH) responsive proteins and protein expression patterns by short-term recombinant human growth hormone (rhGH) therapy in patients with idiopathic short stature (ISS) using proteomic analysis. Seventeen children (14 males and three females) with ISS were included. They were treated with rhGH at a dose of 0.31 ± 0.078 mg/kg/week for 3 months. Immunodepletion of six highly-abundant serum proteins followed by 2D DIGE analysis, and subsequent MALDI TOF MS, were employed to generate a panel of proteins differentially expressed after short-term rhGH therapy and verify the differences in serum levels of specific proteins by rhGH therapy. Fourteen spots were differentially expressed after rhGH treatment. Among them, apo E and apo L-1 expression were consistently enhanced, whereas serum amyloid A was reduced after rhGH therapy. The differential expressions of these proteins were subsequently verified by Western blot analysis using sera of the before and after rhGH treatment. This study suggests that rhGH therapy influences lipoprotein metabolism and enhances apo L-1 protein expression in ISS patients.