OBJECTIVE: To characterize the phenotype spectrum, diagnosis, and response to growth-promoting therapy in patients with ACAN variants causing familial short stature.
METHODS: Three families with ACAN variants causing short stature were reported. Similar cases in the literature were summarized, and the genotype and phenotype were analyzed.
RESULTS: Three novel heterozygous variants, c.757+1G>A, (splicing), c.6229delG, p.(Asp2078Tfs*1), and c.6679C>T, p.(Gln2227*) in the ACAN gene were identified. A total of 314 individuals with heterozygous variants from 105 families and 8 individuals with homozygous variants from 4 families were confirmed to have ACAN variants from literature and our 3 cases. Including our 3 cases, the variants reported comprised 33 frameshift, 39 missense, 23 nonsense, 5 splicing, 4 deletion, and 1 translocation variants. Variation points are scattered throughout the gene, while exons 12, 15, and 10 were most common (25/105, 11/105, and 10/105, respectively). Some identical variants existing in different families could be hot variants, c.532A>T, p.(Asn178Tyr), c.1411C>T, p.(Gln471*), c.1608C>A, p.(Tyr536*), c.2026+1G>A, (splicing), and c.7276G>T, p.(Glu2426*). Short stature, early-onset osteoarthritis, brachydactyly, midfacial hypoplasia, and early growth cessation were the common phenotypic features. The 48 children who received rhGH (and GnRHa) treatment had a significant height improvement compared with before (-2.18 ± 1.06 SD vs. -2.69 ± 0.95 SD, p < 0.001). The heights of children who received rhGH (and GnRHa) treatment were significantly improved compared with those of untreated adults (-2.20 ± 1.10 SD vs. -3.24 ± 1.14 SD, p < 0.001).
CONCLUSIONS: Our study achieves a new understanding of the phenotypic spectrum, diagnosis, and management of individuals with ACAN variants. No clear genotype-phenotype relationship of patients with ACAN variants was found. Gene sequencing is necessary to diagnose ACAN variants that cause short stature. In general, appropriate rhGH and/or GnRHa therapy can improve the adult height of affected pediatric patients caused by ACAN variants.

UNASSIGNED: Floating-Harbor syndrome (FHS) is a rare autosomal dominant inherited disease characterized primarily by short stature, delayed language development, and typical facial features. There are currently few case reports, diagnoses and treatments for these syndromes at home and abroad.
UNASSIGNED: This study reports a case of a boy with \"growth and language development delay\" as the predominant clinical manifestation. FHS was clinically diagnosed based on his growth hormone (GH) deficiency, significant bone age delay, left testicular hydrocele, and the whole exon gene in peripheral blood, which indicated heterozygous mutation of SRCAP gene. Following the treatment with recombinant human GH (rhGH), the child exhibited height increase benefits, and his articulation improved after language therapy.
UNASSIGNED: Genetic testing facilitates early detection, diagnosis, and treatment of the FHS. Additionally, treatment with rhGH effectively increases the height of these children, and language rehabilitation is especially important for their language development.

OBJECTIVE: This study was performed to investigate the effectiveness of the combination of letrozole and recombinant human growth hormone (rhGH) to improve the predicted adult height (PAH) and final adult height (FAH) of Chinese short pubertal boys.
METHODS: In total, 171 Chinese short pubertal boys were recruited for this study. 96 of them received letrozole (2.5 mg/d) combined with rhGH (33.3-66.6 μg/kg.d), and the others received rhGH alone. Follow-up visits were conducted at 1, 3, 6, 9, and 12 months or regularly after the first treatment. During each visit, plasma samples were collected for clinical tests and biomedical analyses, all of which were performed according to standard protocols. This study was registered at www.chictr.org.cn under ID number ChiCTR1900026142.
RESULTS: After receiving treatment for at least 3 months, 68 boys (91 %) in the rhGH therapy group and 90 (94 %) in the letrozole combined with rhGH (letrozole+rhGH) therapy group achieved an increase in PAH, with the latter treatment leading to a more effective slowing of bone age (BA) advancement. Moreover, the increased PAH showed a significant positive correlation with treatment time in both groups, and letrozole+rhGH increased the PAH to a greater degree than rhGH alone (p=0.0023). And letrozole+rhGH not only slowed the increase in BA more efficiently than rhGH therapy alone (p=0.0025), but also achieved a higher FAH (p=0.0078).
CONCLUSIONS: Letrozole combined with rhGH treatment is a promising therapy to increase the PAH and FAH of Chinese short pubertal boys.

Pathogenic variants in the transcription factor CCCTC-binding factor (CTCF) are associated with mental retardation, autosomal dominant 21 (MRD21, MIM#615502). Current studies supported the strong relationship between CTCF variants and growth, yet the mechanism of CTCF mutation leading to short stature is not known. Clinical information, treatment regimens, and follow-up outcomes of a patient with MRD21 were collected. The possible pathogenic mechanisms of CTCF variants leading to short stature were investigated using immortalized lymphocyte cell lines (LCLs), HEK-293T, and immortalized normal human liver cell lines (LO2). This patient received long-term treatment with recombinant human growth hormone (rhGH) which resulted in an increased height of 1.0 SDS. She had low serum insulin-like growth factor 1 (IGF1) before the treatment and the IGF1 level was not significantly increased during the treatment (-1.38 ± 0.61 SDS). The finding suggested that the CTCF R567W variant could have impaired IGF1 production pathway. We further demonstrated that the mutant CTCF had a reduced ability to bind to the promoter region of IGF1, consequently significantly reducing the transcriptional activation and expression of IGF1. Our novel results demonstrated a direct positive regulation of CTCF on the transcription of the IGF1 promoter. The impaired IGF1 expression due to CTCF mutation may explain the substandard effect of rhGH treatment on MRD21 patients. This study provided novel insights into the molecular basis of CTCF-associated disorder.

To evaluate the safety and efficacy of daily somatropin (Jintropin®), a recombinant human growth hormone, in prepubertal children with ISS in China.
This study was a multicenter, randomized, controlled, open-label, phase 3 study. All subjects were randomized 3:1 to daily somatropin 0.05 mg/kg/day or no treatment for 52 weeks. A total of 481 subjects with a mean baseline age of 5.8 years were enrolled in the study. The primary endpoint was change in (△) height standard deviation score (HT-SDS) for chronological age (CA). Secondary endpoints included △height from baseline; △bone age (BA)/CA; △height velocity (HV) and △insulin-like growth factor 1 (IGF-1 SDS).
△HT-SDS at week 52 was 1.04 ± 0.31 in the treatment group and 0.20 ± 0.33 in the control group (P < 0.001). At week 52, statistical significance was observed in the treatment group compared with control for △height (10.19 ± 1.47 cm vs. 5.85 ± 1.80 cm; P < 0.001), △BA/CA (0.04 ± 0.09 vs. 0.004 ± 0.01; P < 0.001), △HV (5.17 ± 3.70 cm/year vs. 0.75 ± 4.34 cm/year; P < 0.001), and △IGF-1 SDS (2.31 ± 1.20 vs. 0.22 ± 0.98; P < 0.001). The frequencies of treatment-emergent adverse events (TEAEs) were similar for the treatment and the control groups (89.8% vs. 82.4%); most TEAEs were mild to moderate in severity and 23 AEs were considered study-drug related.
Daily subcutaneous administration of somatropin at 0.05 mg/kg/day for 52 weeks demonstrated improvement in growth outcomes and was well tolerated with a favorable safety profile.
ClinicalTrials.gov (identifier: NCT03635580). URL: https://clinicaltrials.gov/ct2/show/NCT03635580.

UNASSIGNED: The safety of recombinant human growth hormone (rhGH) treatment in childhood and the role of rhGH therapy in promoting tumorigenesis and progression have been the subject of debate for decades. We aimed to systematically assess the relationship between rhGH therapy in children and adolescents and clinical outcomes, including all-cause mortality, cancer mortality, cancer incidence, and risk of the second neoplasm.
UNASSIGNED: Literature retrieval, study selection, and data extraction were completed independently and in duplicate. Effect-size estimates are expressed as standardized mortality ratios (SMRs), standardized incidence ratio (SIR), and relative risk (RR) with a 95% CI.
UNASSIGNED: Data from 24 articles, involving 254,776 persons, were meta-analyzed. Overall analyses revealed the association of rhGH therapy was not statistically significant with all-cause mortality (SMR = 1.28; 95% CI: 0.58-2.84; P = 0.547; I 2 = 99.2%; Tau2 = 2.154) and cancer mortality (SMR = 2.59; 95% CI: 0.55-12.09; P = 0.228; I 2 = 96.7%; Tau2 = 2.361) and also cancer incidence (SIR = 1.54; 95% CI: 0.68-3.47; P = 0.229; I 2 = 97.5%; Tau2 = 2.287), yet statistical significance was observed for second neoplasm (RR = 1.77; 95% CI: 1.33-2.35; P = 0.001; I 2 = 26.7%; Tau2 = 0.055). Differences in the geographic region, gender, treatment duration, mean rhGH dose, overall rhGH exposure dose, and initial disease accounted for heterogeneity in the subgroup analyses.
UNASSIGNED: Our findings indicate that the rhGH therapy is not related to all-cause mortality and cancer mortality and cancer incidence, yet it seems to trigger a second tumor risk. Future prospective studies are needed to confirm our findings and answer the more challenging question regarding the optimal dose of rhGH therapy in children and adolescents.

Objective: There are numerous reasons for short stature, including mutations in osteochondral development genes. ACAN, one such osteochondral development gene whose heterozygous mutations can cause short stature, has attracted attention from researchers in recent years. Therefore, we analysed six cases of short stature with heterozygous ACAN mutations and performed a literature review. Methods: Clinical information and blood samples from six probands and their family members were collected after consent forms were signed. Gene mutations in the probands were detected by whole-exome sequencing. Then, we searched the literature, performed statistical analysis and summarized the characteristics of all reported cases. Results: We identified six novel mutations of ACAN: c.1411C>T, c.1817C>A, c.1762C>T, c.2266G>C, c.7469G>A and c.1733-1G>A. In the literature, more than 200 affected individuals have been diagnosed genetically with a similar condition (height=-3.14±1.15 standard deviation score (SDS)). Among affected individuals receiving growth promoting treatment, their heights before and after treatment was -2.92±1.07 SDS vs. -2.14±1.23 SDS (p<0.001). As of July 1st, 2019, fifty-seven heterozygous ACAN mutations causing non-syndromic short stature had been reported, including the six novel mutations found in our study. Approximately half of these mutations can lead to protein truncation. Conclusions: This study used clinical and genetic means to examine the relationship between the ACAN gene and short stature. To some extent, clear diagnosis is difficult, since most of these affected individuals\' characteristics are not prominent. Growth promoting therapies maybe beneficial for increasing their heights.

ABSTACT Recombinant human Growth Hormone (rhGH) is an important protein for human growth and is in high demand in clinics. Hence, it is necessary to develop an efficient fermentation process to produce highly pure rhGH. In this study, rhGH was expressed in Escherichia coli under alkaline phosphatase (phoA) promoter. The cultivation conditions for high expression level and purity of rhGH were investigated. The best initial phosphate concentration for rhGH expression, out of the 4 levels of initial phosphate concentration tests performed, was 12.6 mmol/L. Subsequently, 2 fed-batch cultivations under low dissolved oxygen (DO) (0% - 10%) and high DO (20% - 30%) conditions were carried out. High purity rhGH (92%) was obtained from 20% - 30% DO-stat cultivation, although the biomass did not show any significant difference. In summary, this research provided an efficient fermentation process for high purity rhGH production from E. coli under phoA promoter, which can lower the production and purification costs for large-scale production of rhGH.