Clinical Profiles and Genetic Spectra of 814 Chinese Children With Short Stature

A polygenic score for height identifies an unmeasured genetic predisposition among pediatric patients with idiopathic short stature

Background

A subset of children with short stature do not have an identified clinical explanation and are assigned a diagnosis of idiopathic short stature (ISS). We hypothesized that a polygenic score for height (PGSheight) could identify children with ISS who have an unrecognized heritable predisposition to shorter height.

Methods

We examined 534 pediatric participants in an EHR-linked DNA biobank (BioVU) who had undergone an evaluation for short stature by an endocrinologist. We used a previously validated PGSheight and standardized it to a standard deviation (SDS) of 1. PGSheight differences between short stature subtypes was estimated using Tukey's HSD. The PGSheight and mid-parental height (MPH) were then used to predict adult heights for each participant and these predictions were compared using Cohen's d stratifying by short stature subtype. The ability of the PGSheight to discriminate between ISS and short stature due to underlying disease was evaluated using logistic regression models with area under the ROC curve (AUC) analyses and testing the incremental benefit (ΔAUC) of adding the PGSheight to prediction models.

Results

Among the 534 participants, 22.1% had ISS (median [IQR] PGSheight SDS = -1.31 [-2.15 to -0.47]), 6.6% had familial (genetic) short stature (FSS) (-1.62 [-2.13 to -0.54]), and 45.1% had short stature due to underlying pathology (-0.74 [-1.23 to -0.19]). Children with ISS had similar PGSheight values as those with FSS (ΔPGSheight [95% CI] = 0.19 [-0.31 to 0.70], p = 0.75), but predicted heights generated by the PGSheight were lower than the MPH estimate for children with ISS (d = -0.64; p = 4.0×10-18) but not FSS (d = 0.05; p = 0.46), suggesting that MPH underestimates height in the ISS group. Children with ISS had lower PGSheight values than children with pathology (ΔPGSheight = -0.60 SDS [-0.89 to -0.31], p < 0.001), suggesting children with ISS have a larger predisposition to shorter height. In addition, the PGSheight improved model discrimination between ISS and pathologic short stature (ΔAUC, + 0.07 [95% CI, 0.01 to 0.11]).

Conclusions

Some children with ISS have a clinically unrecognized polygenic predisposition to shorter height that is comparable to children with FSS and larger than those with underlying pathology. A PGSheight could help clinicians identify children who have a benign predisposition to shorter height.

Molecular diagnosis of patients with syndromic short stature identified by trio whole-exome sequencing

Background

Short stature is a complex disorder with phenotypic and genetic heterogeneity. This study aimed to investigate clinical phenotypes and molecular basis of a cohort of patients with short stature.

Methods

Trio whole-exome sequencing (Trio-WES) was performed to explore the genetic aetiology and obtain a molecular diagnosis in twenty Chinese probands with syndromic and isolated short stature.

Results

Of the twenty probands, six (6/20, 30%) patients with syndromic short stature obtained a molecular diagnosis. One novel COMP pathogenic variant c.1359delC, p.N453fs*62 and one LZTR1 likely pathogenic variant c.509G>A, p.R170Q were identified in a patient with short stature and skeletal dysplasia. One novel de novo NAA15 pathogenic variant c.63T>G, p.Y21X and one novel de novo KMT2A pathogenic variant c.3516T>A, p.N1172K was identified in two probands with short stature, intellectual disability and abnormal behaviours, respectively. One patient with short stature, cataract, and muscle weakness had a de novo POLG pathogenic variant c.2863 T>C, p.Y955H. One PHEX pathogenic variant c.1104G>A, p.W368X was identified in a patient with short stature and rickets. Maternal uniparental disomy 7 (mUPD7) was pathogenic in a patient with pre and postnatal growth retardation, wide forehead, triangular face, micrognathia and clinodactyly. Thirteen patients with isolated short stature had negative results.

Conclusion

Trio-WES is an important strategy for identifying genetic variants and UPD in patients with syndromic short stature, in which dual genetic variants are existent in some individuals. It is important to differentiate between syndromic and isolated short stature. Genetic testing has a high yield for syndromic patients but low for isolated patients.

Insights into the ANKRD11 variants and short-stature phenotype through literature review and ClinVar database search

Ankyrin repeat domain containing-protein 11 (ANKRD11), a transcriptional factor predominantly localized in the cell nucleus, plays a crucial role in the expression regulation of key genes by recruiting chromatin remodelers and interacting with specific transcriptional repressors or activators during numerous biological processes. Its pathogenic variants are strongly linked to the pathogenesis and progression of multisystem disorder known as KBG syndrome. With the widespread application of high-throughput DNA sequencing technologies in clinical medicine, numerous pathogenic variants in the ANKRD11 gene have been reported. Patients with KBG syndrome usually exhibit a broad phenotypic spectrum with a variable degree of severity, even if having identical variants. In addition to distinctive dental, craniofacial and neurodevelopmental abnormalities, patients often present with skeletal anomalies, particularly postnatal short stature. The relationship between ANKRD11 variants and short stature is not well-understood, with limited knowledge regarding its occurrence rate or underlying biological mechanism involved. This review aims to provide an updated analysis of the molecular spectrum associated with ANKRD11 variants, investigate the prevalence of the short stature among patients harboring these variants, evaluate the efficacy of recombinant human growth hormone in treating children with short stature and ANKRD11 variants, and explore the biological mechanisms underlying short stature from both scientific and clinical perspectives. Our investigation indicated that frameshift and nonsense were the most frequent types in 583 pathogenic or likely pathogenic variants identified in the ANKRD11 gene. Among the 245 KBGS patients with height data, approximately 50% displayed short stature. Most patients showed a positive response to rhGH therapy, although the number of patients receiving treatment was limited. ANKRD11 deficiency potentially disrupts longitudinal bone growth by affecting the orderly differentiation of growth plate chondrocytes. Our review offers crucial insights into the association between ANKRD11 variants and short stature and provides valuable guidance for precise clinical diagnosis and treatment of patients with KBG syndrome.

Clinical profiles and molecular genetic analyses of 98 Chinese children with short statures

Background

Short stature is one of the most prevalent endocrine disorders in children, and its genetic basis is a complex and actively researched subject. Currently, there is limited genetic research on exome sequencing for short stature, and more large-scale studies are necessary for further exploration.

Methods

The retrospective study entailed investigation of 98 Chinese children with short statures (height SDS ≤ -2.5) of unknown etiologies recruited between 2017 and 2021. Whole-exome sequencing (WES) was performed on these patients to identify the potential genetic etiologies. The clinical data were reviewed retrospectively to assess the pathogenicity of the identified mutations. Additionally, 31 patients consented to and received recombinant human growth hormone (rhGH) therapy for 12 months. The short-term effects of rhGH treatment were evaluated across different etiologies of patients with short statures.

Results

The WES results were used to identify 31 different variants in 18 genes among 24 (24.5%) patients. Individuals with more severe short statures were more likely to have underlying genetic etiologies. Short stature accompanied by other phenotypes had significantly higher diagnostic yields than simple severe short stature. The rhGH therapy demonstrated efficacy in most children. Nevertheless, the treatment response was suboptimal in a boy diagnosed with 3M syndrome.

Conclusion

WES is an important approach for confirming genetic disorders in patients with severe short statures of unknown etiologies, suggesting that it could be used as a primary diagnostic strategy. The administration of rhGH may not be suitable for all children with short statures, and the identification of the genetic cause of short stature by WES has significant guidance value for rhGH treatment.

Genetic Findings in Short Turkish Children Born to Consanguineous Parents

INTRODUCTION

The diagnostic yield of genetic analysis in the evaluation of children with short stature depends on associated clinical characteristics, but the additional effect of parental consanguinity has not been well documented.

METHODS

This observational case series of 42 short children from 34 consanguineous families was collected by six referral centres of paediatric endocrinology (inclusion criteria: short stature and parental consanguinity). In 18 patients (12 families, group 1), the clinical features suggested a specific genetic defect in the growth hormone (GH) insulin-like growth factor I (IGF-I) axis, and a candidate gene approach was used. In others (group 2), a hypothesis-free approach was chosen (gene panels, microarray analysis, and whole exome sequencing) and further subdivided into 11 patients with severe short stature (height <-3.5 standard deviation score [SDS]) and microcephaly (head circumference <-3.0 SDS) (group 2a), 10 patients with syndromic short stature (group 2b), and 3 patients with nonspecific isolated GH deficiency (group 2c).

RESULTS

In all 12 families from group 1, (likely) pathogenic variants were identified in GHR, IGFALS, GH1, and STAT5B. In 9/12 families from group 2a, variants were detected in PCNT, SMARCAL1, SRCAP, WDR4, and GHSR. In 5/9 families from group 2b, variants were found in TTC37, SCUBE3, NSD2, RABGAP1, and 17p13.3 microdeletions. In group 2c, no genetic cause was found. Homozygous, compound heterozygous, and heterozygous variants were found in 21, 1, and 4 patients, respectively.

CONCLUSION

Genetic testing in short children from consanguineous parents has a high diagnostic yield, especially in cases of severe GH deficiency or insensitivity, microcephaly, and syndromic short stature.

Role of genetic investigation in the diagnosis of short stature in a cohort of Italian children

BACKGROUND

Short stature (SS) is defined as height more than 2 standard deviations below the mean for age and sex. Hypothyroidism, celiac disease, growth hormone deficiency, hormonal abnormalities, and genetic conditions are among its causes. A wide range of conditions often due to largely unknown genetic variants can elude conventional diagnostic workup.

AIM

We used next-generation sequencing (NGS) to better understand the etiology of SS in a cohort of Italian children.

PATIENTS AND METHODS

The study sample was 125 children with SS of unknown origin referred to our Institute between 2015 and 2021. All had undergone complete auxological and hormonal investigations to exclude common causes of SS. Genetic analysis was performed using a NGS panel of 104 genes. Clinical data were reviewed to clarify the pathogenicity of the variants detected.

RESULTS

In this cohort, 43 potentially causing variants were identified in 38 children. A syndromic genetic condition was diagnosed in 7: Noonan syndrome in 3, Leri-Weill syndrome in 3, and hypochondroplasia in 1. Moreover, 8 benign variants and other 37 like benign variants were found. In 88 children, 179 variants of uncertain significance (VUS) were identified. No variant was found in 16 children.

CONCLUSION

Genetic analysis is a useful tool in the diagnostic workup of patients with SS, in adapting management and treatment, and in identifying syndromes with mild atypical clinical features. The role of VUS should not be underestimated, particularly when multiple VUS with possible mutual worsening effects are present in the same child.

A study on genotypes and phenotypes of short stature caused by epigenetic modification gene variants

Mendelian disorders of the epigenetic machinery (MDEMs) are caused by genetic mutations, a considerable fraction of which are associated with epigenetic modification. These MDEMs exhibit phenotypic overlap broadly characterized by multiorgan abnormalities. The variant detected in genes associated with epigenetic modification can lead to short stature accompanied with multiple system abnormalities. This study is aimed at presenting and summarizing the diagnostic rate, clinical, and genetic profile of MDEMs-associated short stature. Two hundred and fourteen short-stature patients with multiorgan abnormalities were enrolled. Clinical information and whole exome sequence (WES) were analyzed for these patients. WES identified 33 pathogenic/likely pathogenic variants in 19 epigenetic modulation genes (KMT2A, KMT2D, KDM6A, SETD5, KDM5C, HUWE1, UBE2A, NIPBL, SMC1A, RAD21, CREBBP, CUL4B, BPTF, ANKRD11, CHD7, SRCAP, CTCF, MECP2, UBE3A) in 33 patients (15.4%). Of note, 19 variants had never been reported previously. Furthermore, these 33 variants were associated with 16 different disorders with overlapping clinical features characterized by development delay/intelligence disability (31/33; 93.9%), small hands (14/33; 42.4%), clinodactyly of the 5th finger (14/33; 42.4%), long eyelashes (13/33; 39.4%), and hearing impairment (9/33; 27.3%). Additionally, several associated phenotypes are reported for the first time: clubbing with KMT2A variant, webbed neck with SETD5 variant, retinal detachment with CREBBP variant, sparse lateral eyebrow with HUWE1 variant, and long palpebral fissure with eversion of the lateral third of the low eyelid with SRCAP variant.Conclusions: Our study provided a new conceptual framework for further understanding short stature. Specific clinical findings may indicate that a short-stature patient may have an epigenetic modified gene variant.

Two Chinese Patients of Auriculocondylar Syndrome 2: A Novel PLCB4 Splicing Variant and 5-Year Follow-up

OBJECTIVE

Auriculocondylar syndrome (ARCND) is a set of rare craniofacial malformations characterized by variable micrognathia, ear malformations, and mandibular condyle hypoplasia, and other accompanying features with phenotypic complexity. ARCND2 caused by pathogenic variants in the PLCB4 gene is a very rare disease with less than 50 patients reported and only 36 different variants of the PLCB4 gene recorded in HGMD. This study aims to enrich the patient resources, clinical data and mutational spectrum of ARCND2.

DESIGN

Case series study.

SETTING

Guangzhou Women and Children's Medical Center and Guangdong Women and Children Hospital.

PATIENTS

Two Chinese patients with ARCND2.

MAIN OUTCOME MEASURES

Clinical, radiological and molecular findings.

RESULTS

Both the two patients presented with craniofacial and ear malformations, and feeding difficulties. Whole exome sequencing identified two different variants of the PLCB4 gene in these two patients with a heterozygous allele and a de novo mode of inheritance respectively. Patient 1 carried a known pathogenic c.1861C > T(p.Arg621Cys) missense variant, whereas Patient 2 had a novel c.225 + 1G > A splicing variant. Sanger sequencing confirmed the presence of PLCB4 variants in the proband and absence in the unaffected parents. These two PLCB4 variants were suggested as disease-causing candidates for these two patients. During a 5-year follow-up, Patient 2 gradually manifested crowded teeth, underweight, motor delay and intellectual disability.

CONCLUSIONS

In this study, we report two Chinese patients with ARCND2, describe their clinical and mutational features, and share a 5-year follow-up of one patient. Our study adds two additional patients to ARCND2, reveals a novel PLCB4 variant, and expands the phenotypic and genotypic spectrum.

Genetic evaluation using next-generation sequencing of children with short stature: a single tertiary-center experience

PURPOSE

We used next-generation sequencing (NGS) to investigate the genetic causes of suspected genetic short stature in 37 patients, and we describe their phenotypes and various genetic spectra.

METHODS

We reviewed the medical records of 50 patients who underwent genetic testing using NGS for suspected genetic short stature from June 2019 to December 2022. Patients with short stature caused by nongenetic factors or common chromosomal abnormalities were excluded. Thirty-seven patients from 35 families were enrolled in this study. We administered one of three genetic tests (2 targeted panel tests or whole exome sequencing) to patients according to their phenotypes.

RESULTS

Clinical and molecular diagnoses were confirmed in 15 of the 37 patients, for an overall diagnostic yield of 40.5%. Fifteen pathogenic/likely pathogenic variants were identified in 13 genes (ACAN, ANKRD11, ARID1B, CEP152, COL10A1, COL1A2, EXT1, FGFR3, NIPBL, NRAS, PTPN11, SHOX, SLC16A2). The diagnostic rate was highest in patients who were small for their gestational age (7 of 11, 63.6%).

CONCLUSION

Genetic evaluation using NGS can be helpful in patients with suspected genetic short stature who have clinical and genetic heterogeneity. Further studies are needed to develop patient selection algorithms and panels containing growth-related genes.

Molecular diagnosis is an important indicator for response to growth hormone therapy in children with short stature

BACKGROUND

Significant differences have been observed in the efficacy of recombinant human growth hormone (rhGH) treatment for short children. The present study aimed to identify the genetic etiology of short stature and to assess the role of molecular diagnosis in predicting responses to rhGH treatment.

METHODS

A total of 407 short children were included in the present study, 226 of whom received rhGH treatment. Whole-exome sequencing (WES) was conducted on short children to identify the underlying genetic etiology. Correlations between molecular diagnosis and the efficacy of rhGH treatment were examined.

RESULTS

Pathogenic or likely pathogenic mutations were identified in 86 of the 407 patients (21.1%), including 36 (41.9%) novel variants. Among the multiple pathways affecting short stature, genes involved in fundamental cellular processes (38.7%) play a larger role, especially the RAS-MAPK pathway. In general, patients without pathogenic mutations responded better to rhGH than those with mutations. Furthermore, patients with hormone signaling pathway mutations had a better response to rhGH, while those with paracrine factor mutations had a worse response to rhGH.

CONCLUSIONS

This study highlights the utility of WES in identifying genetic etiology in children with short stature. Identifying likely causal mutations is an important factor in predicting rhGH response.

A novel 11 base pair deletion in KMT2C resulting in Kleefstra syndrome 2

BACKGROUND

Haploinsufficiency of the Lysine Methyltransferase 2C (KMT2C) gene results in the autosomal dominant disorder, Kleefstra syndrome 2. It is an extremely rare neurodevelopmental condition, with 14 previous reports describing varied clinical manifestations including dysmorphic features, delayed psychomotor development and delayed growth.

METHODS

Here, we describe a female with global developmental delay, attention deficit disorder, dyspraxia, short stature and subtle non-specific dysmorphic features. To identify causative mutations, whole exome sequencing was performed on the proband and her younger brother with discrete clinical presentation.

RESULTS

Whole exome sequencing identified a novel de novo heterozygous 11 bp deletion in KMT2C (c.1759_1769del), resulting in a frameshift mutation and early termination of the protein (p.Gln587SerfsTer7). This variant is the second-most N-terminal reported mutation, located 4171 amino acids upstream of the critical enzymatically active SET domain (required for chromatin modification and histone methylation).

CONCLUSION

The majority of the other reported mutations are frameshift mutations upstream of the SET domain and are predicted to result in protein truncation. It is thought that truncation of the SET domain, results functionally in an inability to modify chromatin through histone methylation. This report expands the clinical and genetic characterisation of Kleefstra syndrome 2.

Molecular Diagnostic Yield of Exome Sequencing and Chromosomal Microarray in Short Stature: A Systematic Review and Meta-Analysis

Importance

Currently, the diagnostic yield of exome sequencing (ES) and chromosomal microarray analysis (CMA) for short stature cohorts is uncertain. Despite previous studies reporting the widespread use of ES and CMA, a definitive diagnostic yield has not been established.

Objective

To investigate the diagnostic yield of ES and CMA in short stature.

Data Sources

A systematic literature search was conducted using relevant keywords in 3 databases (PubMed, Embase, and Web of Science) in February 2023.

Study Selection

Eligible studies for meta-analysis were those that had at least 10 participants with short stature who were diagnosed using either ES or CMA and the number of diagnosed patients was reported. Of 5222 identified studies, 20 were eventually included in the study.

Data Extraction and Synthesis

Two independent investigators extracted relevant information from each study, which was then synthesized using proportional meta-analysis to obtain the overall diagnostic yield of ES and CMA.

Main Outcomes and Measures

The primary outcome measure was to determine the overall diagnostic yield of ES and CMA. A subgroup meta-analysis was also performed to assess if the diagnostic yield varied depending on whether ES was used as a first-tier or last-resort test. Additionally, a meta-regression was carried out to investigate how the diagnostic yield varied over time.

Results

Twenty studies were included, comprising 1350 patients with short stature who underwent ES and 1070 patients who completed CMA. The overall diagnostic yield of ES among the cohorts and CMA among the cohorts was found to be 27.1% (95% CI, 18.1%-37.2%) and 13.6% (95% CI, 9.2%-18.7%), respectively. No statistically significant difference was observed between the first-tier (27.8%; 95% CI, 15.7%-41.8%) and last-resort groups (25.6%; 95% CI, 13.6%-39.6%) (P = .83) or in the percentage of positively diagnosed patients over time. No statistically significant difference was observed between the first-tier (27.8%; 95% CI, 15.7%-41.8%) and last-resort groups (25.6%; 95% CI, 13.6%-39.6%) (P = .83) or in the percentage of positively diagnosed patients over time.

Conclusion and Relevance

This systematic review and meta-analysis provides high-level evidence supporting the diagnostic efficacy of ES and CMA in patients with short stature. The findings serve as a solid reference for clinicians when making informed decisions about recommending these genetic tests.

Assessment of Nutritional Status in the Diagnostic Evaluation of the Child with Growth Failure

Current clinical guidelines provide information about the diagnostic workup of children with growth failure. This mini-review focuses on the nutritional assessment, which has received relatively little attention in such guidelines. The past medical history, in particular a low birth size and early feeding problems, can provide information that can increase the likelihood of nutritional deficits or several genetic causes. The current medical history should include a dietary history and can thereby reveal a poorly planned or severely restricted diet, which can be associated with nutritional deficiencies. Children on a vegan diet should receive various nutritional supplements, but insufficient compliance has been reported in one-third of cases. While proper use of nutritional supplements in children consuming a vegan diet appears to be associated with normal growth and development, insufficient intake of supplements may impede growth and bone formation. Physical examination and analysis of height and weight over time can help differentiating between endocrine causes, gastrointestinal disorders, psychosocial problems, or underlying genetic conditions that prevent adequate nutritional intake. Laboratory screening should be part of the workup in every child with short stature, and further laboratory tests can be indicated if warranted by the dietary history, especially in children on a poorly planned vegan diet.

The Genetic Landscape of Children Born Small for Gestational Age with Persistent Short Stature

INTRODUCTION

Among children born small for gestational age, 10-15% fail to catch up and remain short (SGA-SS). The underlying mechanisms are mostly unknown. We aimed to decipher genetic aetiologies of SGA-SS within a large single-centre cohort.

METHODS

Out of 820 patients treated with growth hormone (GH), 256 were classified as SGA-SS (birth length and/or birth weight <-2 SD for gestational age and life-minimum height <-2.5 SD). Those with the DNA triplet available (child and both parents) were included in the study (176/256). Targeted testing (karyotype/FISH/MLPA/specific Sanger sequencing) was performed if a specific genetic disorder was clinically suggestive. All remaining patients underwent MS-MLPA to identify Silver-Russell syndrome, and those with unknown genetic aetiology were subsequently examined using whole-exome sequencing or targeted panel of 398 growth-related genes. Genetic variants were classified using ACMG guidelines.

RESULTS

The genetic aetiology was elucidated in 74/176 (42%) children. Of these, 12/74 (16%) had pathogenic or likely pathogenic (P/LP) gene variants affecting pituitary development (LHX4, OTX2, PROKR2, PTCH1, POU1F1), the GH-IGF-1 or IGF-2 axis (GHSR, IGFALS, IGF1R, STAT3, HMGA2), 2/74 (3%) the thyroid axis (TRHR, THRA), 17/74 (23%) the cartilaginous matrix (ACAN, various collagens, FLNB, MATN3), and 7/74 (9%) the paracrine chondrocyte regulation (FGFR3, FGFR2, NPR2). In 12/74 (16%), we revealed P/LP affecting fundamental intracellular/intranuclear processes (CDC42, KMT2D, LMNA, NSD1, PTPN11, SRCAP, SON, SOS1, SOX9, TLK2). SHOX deficiency was found in 7/74 (9%), Silver-Russell syndrome in 12/74 (16%) (11p15, UPD7), and miscellaneous chromosomal aberrations in 5/74 (7%) children.

CONCLUSIONS

The high diagnostic yield sheds a new light on the genetic landscape of SGA-SS, with a central role for the growth plate with substantial contributions from the GH-IGF-1 and thyroid axes and intracellular regulation and signalling.

Approach to the Patient With Short Stature: Genetic Testing

The first step in the evaluation of the short child is to decide whether growth parameters in the context of the history are abnormal or a variant of normal. If growth is considered abnormal, system and hormonal tests are likely to be required, followed by more directed testing, such as skeletal survey and/or genetic screening with karyotype or microarray. In a small percentage of short children in whom a diagnosis has not been reached, this will need to be followed by detailed genetic analysis; currently, exome sequencing using targeted panels relevant to the phenotype is the commonly used test. Clinical scenarios are presented that illustrate how such genetic testing can be used to establish a molecular diagnosis, and how that diagnosis contributes to the management of the short child. New genetic causes for short stature are being recognized on a frequent basis, while the clinical spectrum for known genes is being extended. We recommend that an international repository for short stature conditions is established for new findings to aid dissemination of knowledge, but also to help in the definition of the clinical spectrum both for new and established conditions.

Long-acting PEGylated growth hormone in children with idiopathic short stature: time to reconsider our diagnostic and treatment policy?

Idiopathic short stature (ISS) is a diagnosis of exclusion, and therefore each child with short stature or slow growth referred to a paediatrician deserves a full medical history and physical examination, as well as radiological and laboratory screening tests. In patients with an increased likelihood of a genetic cause, genetic testing is indicated. Idiopathic short stature is an approved indication for recombinant human growth hormone (rhGH) in the USA but not in most other parts of the world. In a recent article published in this journal, Luo et al reported on the 1-year's results of a multicentre randomized controlled trial (n = 360) on the efficacy and safety of two dosages of long-acting PEGylated rhGH (PEG-rhGH, Jintrolong®) (0.1 or 0.2 mg/kg body weight per week, respectively) in children with ISS compared with an untreated control group. The growth response to the higher dosage was similar to reported data on daily rhGH. In this commentary, we discuss whether the recent data on genetic causes of short stature in children who initially were labelled ISS, and data on the long-term safety of daily rhGH, may influence the balance between risks and benefits of rhGH treatment in children with ISS. We further discuss the pharmacokinetic and -dynamic profile of PEG-rhGH and its potential consequences for long-term safety.

Diagnostic yield of a multigene sequencing approach in children classified as idiopathic short stature

Objective

Most children with short stature remain without an etiologic diagnosis after extensive clinical and laboratory evaluation and are classified as idiopathic short stature (ISS). This study aimed to determine the diagnostic yield of a multigene analysis in children classified as ISS.

Design and methods

We selected 102 children with ISS and performed the genetic analysis as part of the initial investigation. We developed customized targeted panel sequencing, including all genes already implicated in the isolated short-stature phenotype. Rare and deleterious single nucleotide or copy number variants were assessed by bioinformatic tools.

Results

We identified 20 heterozygous pathogenic (P) or likely pathogenic (LP) genetic variants in 17 of 102 patients (diagnostic yield = 16.7%). Three patients had more than one P/LP genetic alteration. Most of the findings were in genes associated with the growth plate differentiation: IHH (n = 4), SHOX (n = 3), FGFR3 (n = 2), NPR2 (n = 2), ACAN (n = 2), and COL2A1 (n = 1) or involved in the RAS/MAPK pathway: NF1 (n = 2), PTPN11 (n = 1), CBL (n = 1), and BRAF (n = 1). None of these patients had clinical findings to guide a candidate gene approach. The diagnostic yield was higher among children with severe short stature (35% vs 12.2% for height SDS ≤ or > -3; P = 0.034). The genetic diagnosis had an impact on clinical management for four children.

Conclusion

A multigene sequencing approach can determine the genetic etiology of short stature in up to one in six children with ISS, removing the term idiopathic from their clinical classification.

Long-acting PEGylated growth hormone in children with idiopathic short stature

OBJECTIVE

To evaluate the safety and efficacy of weekly PEGylated-recombinant human growth hormone (PEG-rhGH) in children with idiopathic short stature (ISS) in China.

DESIGN AND METHODS

This was a multicenter, phase II study in which all subjects were randomized 1:1:1 to weekly s.c. injections of PEG-rhGH 0.1 (low-dose (LD) group) or 0.2 mg/kg/week (high-dose (HD) group) or control for 52 weeks. The primary end point was change (Δ) in height s.d. score (HT-SDS) from baseline to week 52. Secondary end points were height velocity (HV), bone maturity, insulin-like growth factor-1 (IGF-1) SDS, and IGF-1/insulin-like growth factor-binding protein-3 (IGFBP-3) molar ratio.

RESULTS

A total of 360 children with ISS were recruited in the study (n = 120 in each group). At week 52, ΔHT-SDS was 0.56 ± 0.26, 0.98 ± 0.35, and 0.20 ± 0.26 in the LD, HD, and control groups, respectively (within-group P < 0.0001; intergroup P < 0.0001). Statistically significant values of ΔHV, IGF-1, IGF-1/IGFBP-3 ratio, and IGF-1 SDS at week 52 from baseline were observed in both treatment groups (P < 0.0001). There were clear dose-dependent responses for all auxological variables. PEG-rhGH was well tolerated throughout the treatment period with treatment-emergent adverse events (TEAEs) reported in 86.5%, 84.6%, and 91.3% of children in the HD, LD, and control groups, respectively. The incidence of TEAEs was similar in all treatment groups despite the difference in doses. A total of 27 (8.7%) children experienced drug-related TEAEs.

CONCLUSION

Fifty-two-week treatment with PEG-rhGH 0.1 or 0.2 mg/kg/week achieved significant improvement in HT-SDS and other growth-related variables, including HV, IGF-1 SDS, and IGF-1/IGFBP-3 ratio, in a dose-dependent manner. Both doses were well tolerated with similar safety profiles.

Correlation Study between Levels of Gastrin, Serum IGF-1, and GHBP and Growth and Development in Children with Short Stature Based on Big Data Analysis

Objective

To analyze the correlation between the levels of gastrin, serum IGF-1, and GHBP and growth and development in children with short stature (SS) using the big data.

Methods

By means of retrospective analysis, the clinical data of 42 children with SS admitted to our hospital from October 2020 to October 2021 were selected as the study group, while 30 children with the healthy physical examination results in the corresponding period were selected as the control group to measure the growth and development indices and the levels of gastrin, serum IGF-1, and GHBP. The Pearson correlation analysis was used for the relationship between the levels of gastrin, serum IGF-1, and GHBP and growth and development indices in children with SS, and the targeted intervention measures were formulated by the analysis of experimental data.

Results

Compared with the study group, the height, weight, and bone mineral density (BMD) Z-scores of children in the control group were obviously higher (P < 0.001). The levels of gastrin, serum IGF-1, and GHBP in the study group were markedly lower than those in the control group (P < 0.05). The Pearson correlation analysis showed that the gastrin, serum IGF-1, and GHBP of children were positively correlated with growth and development indices (P < 0.001). The levels of gastrin, serum IGF-1, and GHBP in children were distinctly improved after treatment (P < 0.05).

Conclusion

The gastrin, serum IGF-1, and GHBP are closely related to the SS, and the effective clinical intervention can better improve the above indicators of children to promote their growth and development.

Case Report: The success of face analysis technology in extremely rare genetic diseases in Korea: Tatton–Brown–Rahman syndrome and Say–Barber –Biesecker–Young–Simpson variant of ohdo syndrome

Tatton–Brown–Rahman syndrome (TBRS) and Say–Barber–Biesecker– Young–Simpson variant of Ohdo syndrome (SBBYSS) are extremely rare genetic disorders with less than 100 reported cases. Patients with these disorders exhibit a characteristic facial dysmorphism: TBRS is characterized by a round face, a straight and thick eyebrow, and prominent maxillary incisors, whereas SBBYSS is characterized by mask-like facies, blepharophimosis, and ptosis. The usefulness of Face2Gene as a tool for the identification of dysmorphology syndromes is discussed, because, in these patients, it suggested TBRS and SBBYSS within the top five candidate disorders. Face2Gene is useful for the diagnosis of extremely rare diseases in Korean patients, suggesting the possibility of expanding its clinical applications.