Disproportionate Short Stature Research Articles

Comprehensive literature review on the prevalence of comorbid conditions in patients with achondroplasia.

Achondroplasia (ACH) is a rare, genetic condition and is the most common skeletal dysplasia resulting in disproportionate short stature and numerous multi-systemic comorbidities. As we enter an era of new treatment options which may impact comorbidities, it is important to understand the background rates of these events to aid evaluation of potential treatment effects. Thus, the aim of this literature review was to provide a comprehensive quantification of prevalence estimates of comorbidities in achondroplasia by age for use as a compiled reference to assist in quantifying the risk/benefit of new treatment options and informing timely management of ACH. PubMed and Embase databases were searched, complemented by manual bibliography searching, for peer-reviewed articles published between 1975 and 2021, guided by PRISMA principles. Number of patients and the prevalence of specific comorbidities by age were extracted. We calculated exact 95%-confidence limits for the proportion of affected patients (prevalence) and data were presented visually using forest plots. An a priori decision was made not to utilise meta-analytic techniques to pool estimates as we intended to understand the variability in comorbidities by displaying each estimate separately. The literature search identified 206 articles of which 73 were eligible for inclusion. The majority of studies (n=34) had been conducted in the USA or in Europe (n=20). Study designs were mostly retrospective chart reviews (n=33) or small cohort studies (n=19). The availability of literature on particular conditions varied but trended towards a focus on assessment and prevention of severe conditions, such as respiratory conditions in children (21 studies), neurological manifestations (16 studies) and upper spine compression (15 studies). There was substantial heterogeneity in study design, type of clinical setting, populations and use of definitions in reporting comorbidities which need to be considered when interpreting study results. Despite the variability of the studies, comorbidity patterns by age were recognizable. In infants, a high prevalence (>20%) was found for kyphosis, a range of neurological manifestations and sleep apnea. There was also an excess mortality in infancy (4-7.8/100 person-years). Conditions identified in infancy continued to prevail in childhood. Genu varum was highly prevalent from the age children started to walk (9-75%). Other conditions started to emerge in children; those with a high prevalence (>20%) were hearing loss and pain. In adolescence, neurological manifestations in the arm, neck or leg were reported (~15%), consistent with symptomatic spinal stenosis or spinal compression. Fewer studies were available in older populations, especially in adults; however limited data suggest that pain and cardiovascular conditions, particularly excess weight and obesity, became more prevalent into adulthood. Mortality rates increased again in older age-groups. This review provides a reference base of current knowledge of the type and frequency of comorbidities in ACH. This not only allows future contextualisation of new treatment options but supports clinical decision-making on the timely medical management and intervention of ACH. This review also reflects the current medical priorities in the management of ACH, indicating a focus on pediatric care and the complex needs of individuals with ACH involving many different disciplines. Further studies into the natural history of this rare disease using more consistent definitions of comorbidities, especially into adulthood, are needed to elucidate the multi-systemic nature of this condition.

Exploring and expanding the phenotype and genotype diversity in seven Chinese families with spondylo-epi-metaphyseal dysplasia.

Spondylo-epi-metaphyseal dysplasia (SEMD) is a heterogeneous group of disorders with different modes of inheritance and is characterized by disproportionate or proportionate short stature. To date, more than 30 disease-causing genes have been identified, and different types of SEMD exhibit greatly overlapping clinical features, which usually complicate the diagnosis. This study was performed to expand the clinical and molecular spectrum of SEMD among Chinese subjects and to explore their potential phenotype–genotype relations. We enrolled seven families including 11 affected patients with SEMD, and their clinical, radiographic, and genetic data were carefully analyzed. All the seven probands showed different degrees of short stature, and each of them exhibited additional specific skeletal manifestations; four probands had extraosseous manifestations. X-rays of the seven probands showed common features of SEMD, including vertebral deformities, irregular shape of the epiphysis, and disorganization of the metaphysis. Seven variants were identified in TRPV4 (c.694C> T, p.Arg232Cys), COL2A1 (c.654 + 1G > C; c.3266_3268del, p.Gly1089del), CCN6 (c.396 T> G, p.Cys132Trp; c.721 T>C, p.Cys241Arg), SBDS (c.258 + 2T> C), and ACAN (c.1508C> A, p.Thr503Lys) genes, and two of them were novel. Two families with TRPV4 variants showed considerable intrafamily and interfamily heterogeneities. In addition, we reported one case of SEMD with a severe phenotype caused by ACAN gene mutation. Our study expands the phenotype and genetic spectrum of SEMD and provides evidence for the phenotype–genotype relations, aiding future molecular and clinical diagnosis as well as procreative management of SEMD.

Achondroplasia in Latin America: practical recommendations for the multidisciplinary care of pediatric patients

BackgroundAchondroplasia is the most common bone dysplasia associated with disproportionate short stature, and other comorbidities, such as foramen magnum stenosis, thoracolumbar kyphosis, lumbar hyperlordosis, genu varum and spinal compression. Additionally, patients affected with this condition have higher frequency of sleep disorders, ear infections, hearing loss and slowed development milestones. Considering these clinical features, we aimed to summarize the regional experts’ recommendations for the multidisciplinary management of patients with achondroplasia in Latin America, a vast geographic territory with multicultural characteristics and with socio-economical differences of developing countries.MethodsLatin American experts (from Argentina, Brazil, Chile and Colombia) particiáted of an Advisory Board meeting (October 2019), and had a structured discussion how patients with achondroplasia are followed in their healthcare centers and punctuated gaps and opportunities for regional improvement in the management of achondroplasia.ResultsPractical recommendations have been established for genetic counselling, prenatal diagnosis and planning of delivery in patients with achondroplasia. An outline of strategies was added as follow-up guidelines to specialists according to patient developmental phases, amongst them neurologic, orthopedic, otorhinolaryngologic, nutritional and anthropometric aspects, and related to development milestones. Additionally, the role of physical therapy, physical activity, phonoaudiology and other care related to the quality of life of patients and their families were discussed. Preoperative recommendations to patients with achondroplasia were also included.ConclusionsThis study summarized the main expert recommendations for the health care professionals management of achondroplasia in Latin America, reinforcing that achondroplasia-associated comorbidities are not limited to orthopedic concerns.

Articular Manifestations of X-Linked Hypophosphatemic Rickets in Saudi Children: A Retrospective Cohort Study

Introduction: This retrospective cohort study aimed to describe the articular manifestations in Saudi children with X-linked hypophosphatemic rickets (XLHR). Materials and Methods: The medical records of children with XLHR were retrospectively reviewed. The diagnosis of XLHR was confirmed biochemically by low serum phosphorus and elevated alkaline phosphatase, radiologically by the evidence of active rickets and genetically by phosphate-regulating gene with homology to endopeptidases (PHEX) gene mutations. Results: Twenty-two patients with XLHR (10.8 years + 4.9) were enrolled. All children were followed at King Faisal Specialist Hospital & Research Center for a mean duration of 8.7 years (+3.7). Clinically, all patients had disproportionate short stature (-2.5 standard deviation +1.3) with varying degrees of skeletal deformities, including genu varum in 68%, genu valgum in 18%, coxa vara in 14%, bowing of tabia in 32%, and history of fractures in 32% of children. Hearing impairment was noted in two children. Biochemically, all patients showed increased urinary phosphate loss with hypophosphatemia 0.67 mmol/l (+0.15) and elevated serum alkaline phosphatase levels 522 IU/l (+133). Genetically, hemizygous PHEX mutation (C746F) was reported in seven patients. Radiologically, four children had osteoarthritis and three had enthesopathies. Four patients craniosynostosis. All children were on oral inorganic phosphate salts (50–70 mg/kg/day), combined with 1,25(OH)2D3 (alfacalcidol or calcitriol, 30–40 ng/kg/day). Conclusion: Patients with XLHR frequently present with varying degrees of joint deformities that are not completely resolved with either medical or surgical treatment. Long-term skeletal complications of XLHR that present in adults are less common in children and adolescents.

Literature review and expert opinion on the impact of achondroplasia on medical complications and health-related quality of life and expectations for long-term impact of vosoritide: a modified Delphi study

BackgroundAchondroplasia is associated with disproportionate short stature and significant and potentially severe medical complications. Vosoritide is the first medicine to treat the underlying cause of achondroplasia and data from phase 3 and phase 2 extension studies showed effects on growth and body proportions. However, there are currently no long-term data available on the direct impact on endpoints such as medical complications and health-related quality of life (HRQoL). This study explored the perceived impact of achondroplasia on medical complications, HRQoL, healthcare resource use and mortality, and potential modifying effects of vosoritide, based on published evidence and expert opinion. Structured expert opinion was obtained by an international modified Delphi study among 14 experts in managing achondroplasia performed on a virtual platform and consisting of an explorative phase followed by an anonymous individual rating round.ResultsOverall, the panelists expect that in individuals starting long-term treatment between 2 years of age and puberty, growth velocity increases observed in the clinical trials will be maintained until final height is reached (92% agreement) and will likely result in clinically meaningful improvements in upper-to-lower body segment ratio (85%). Earlier treatment initiation will likely result in a greater final height (100%) and more likely improve proportionality (92%) than later treatment. Although current data are limited, ≥ 75% of panelists find it conceivable that the earlier long-term treatment is started, the greater the probability of a positive effect on the lifetime incidence of symptomatic spinal stenosis, kyphosis, obstructive sleep apnea, and foramen magnum stenosis. These are among the most clinically important complications of achondroplasia because of their high impact on comorbidity, mortality, and/or HRQoL. A positive effect of vosoritide on the incidence of surgeries through lifetime was considered more likely with earlier long-term treatment (90%).ConclusionsThis explorative study, based on international expert opinion, provides further insight into the medical and functional impacts of achondroplasia and how these might be modified through long-term use of vosoritide. The results can be used to guide the direction and design of future research to validate the assumptions and to discuss potential treatment outcomes with disease modifying therapies with families and clinicians.

Treatment Goals for Achondroplasia: A Qualitative Study with Parents and Adults.

IntroductionAchondroplasia is characterized by disproportionate short stature accompanied by other changes to the musculoskeletal system. Individuals with this condition typically experience a variety of medical complications. As pharmacologic treatments continue to be developed for the treatment of achondroplasia, it is important to understand treatment goals among those affected by achondroplasia and the factors that shape their goals.MethodsThis qualitative study is based on semi-structured interviews with 19 parents of children with achondroplasia and five adults with achondroplasia in the USA. We employed thematic analysis using an iterative process to identify themes across the interviews.ResultsParticipants had two goals for pharmacologic treatment of achondroplasia: ameliorating complications associated with the condition and increasing stature to overcome functional limitations and psychosocial challenges. Complications of particular concern were chronic pain and surgeries to repair spinal, ear, nose, and throat (ENT) problems, and neurological sequelae. Increased height would enhance independence, help individuals to fit in socially, and avoid social stigma. Countervailing factors included the importance of stature to their identity and the concern that the condition would remain despite treatment.ConclusionsThis study offers evidence about how individuals affected by achondroplasia think about the pharmacologic treatment of this condition, including both the benefits of ameliorating complications and increasing height. The findings can offer practical insights for parents of children considering treatment, treating physicians, and decision-makers evaluating coverage decisions for treatment of achondroplasia.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12325-022-02190-6.

Clinical and Genetic Profile of Children With Short Stature Presenting to a Genetic Clinic in Northern India

To define the spectrum of genetic disorders in patients with short stature visiting the genetic out-patientdepartmentin a tertiary care hospital. A chart review was done for 455 individuals (10 months-16 yrs) with short stature, who were evaluated at the genetic clinic from 1 January, 2017 upto 31 October, 2018. 226 patients who needed detailed evaluation, the spectrum of genetic diagnosis is presented. Proportionate short stature was identified in 63% individuals (n=142) of which 93 (65%) were recognizable syndromes such as Turner syndrome, and William syndrome, and RASopathies. In clinically undefined syndromes (39, 27%), a diagnosis could be made by karyotype (n=3/10), chromosomal microarray (6/12) and exome sequencing (1/6). In the 84 children in the disproportionate short stature group (37%), lysosomal storage disorders (LSDs) (45%, n=38) were identified by enzyme analysis in 86.8% and skeletal dysplasias (44%, n=37) identified by skeletal survey in 89% cases. In undefined syndromic short stature, chromosomal microarray may be the first investigation of choice if phenotyping is not suggestive of a specific genetic syndrome. Exome sequencing can be useful in identifying newer genes among idiopathic and familial short stature cohorts.

Novel COL2A1 variants in Japanese patients with spondyloepiphyseal dysplasia congenita

Spondyloepiphyseal dysplasia congenita (SEDC) is a multisystemic skeletal disorder caused by pathogenic variants in COL2A1. Here, we report the genotype-phenotype correlations in five Japanese patients with SEDC based on their clinical and radiological findings. All five patients had novel missense variants resulting in glycine substitutions (G474V, G543E, G567S, G594R, and G1170R). Genetic testing is important for early intervention for the extraskeletal complications of SEDC. Spondyloepiphyseal dysplasia congenita (SEDC) (OMIM#183900) is an autosomal dominant chondrodysplasia characterized by disproportionate short stature, abnormal epiphyses, flattened vertebral bodies (skeletal abnormalities), and extraskeletal features, including myopia, retinal degeneration with retinal detachment, and cleft palate. SEDC is caused by a heterozygous variant in the collagen II alpha 1 (COL2A1) gene.

Clinical features and FGFR3 mutations of children with achondroplasia

To study the clinical features and fibroblast growth factor receptor 3 (FGFR3) gene mutations of children with achondroplasia (ACH) through an analysis of 17 cases. A retrospective analysis was performed on the clinical data and FGFR3 gene detection results of 17 children with ACH who were diagnosed from January 2009 to October 2021. Of the 17 children with ACH, common clinical manifestations included disproportionate short stature (100%, 17/17), macrocephaly (100%, 17/17), trident hand (82%, 14/17), and genu varum (88%, 15/17). The common imaging findings were rhizomelic shortening of the long bones (100%, 17/17) and narrowing of the lumbar intervertebral space (88%, 15/17). Major complications included skeletal dysplasia (100%, 17/17), middle ear dysfunction (82%, 14/17), motor/language developmental delay (88%, 15/17), chronic pain (59%, 10/17), sleep apnea (53%, 9/17), obesity (41%, 7/17), foramen magnum stenosis (35%, 6/17), and hydrocephalus (24%, 4/17). All 17 children (100%) had FGFR3 mutations, among whom 13 had c.1138G>A hotspot mutations of the FGFR3 gene, 2 had c.1138G>C mutations of the FGFR3 gene, and 2 had unreported mutations, with c.1252C>T mutations of the FGFR3 gene in one child and c.445+2_445+5delTAGG mutations of the FGFR3 gene in the other child. This study identifies the unreported mutation sites of the FGFR3 gene, which extends the gene mutation spectrum of ACH. ACH is a progressive disease requiring lifelong management through multidisciplinary collaboration.

A homozygous hypomorphic BNIP1 variant causes an increase in autophagosomes and reduced autophagic flux and results in a spondylo-epiphyseal dysplasia.

BNIP1 (BCL2 interacting protein 1) is a soluble N-ethylmaleimide-sensitive factor-attachment protein receptor involved in ER membrane fusion. We identified the homozygous BNIP1 intronic variant c.84+3A>T in the apparently unrelated patients 1 and 2 with disproportionate short stature. Radiographs showed abnormalities affecting both the axial and appendicular skeleton and spondylo-epiphyseal dysplasia. We detected ~80% aberrantly spliced BNIP1 pre-mRNAs, reduced BNIP1 mRNA level to ~80%, and BNIP1 protein level reduction by ~50% in patient 1 compared to control fibroblasts. The BNIP1 ortholog in Drosophila, Sec20, regulates autophagy and lysosomal degradation. We assessed lysosome positioning and identified a decrease in lysosomes in the perinuclear region and an increase in the cell periphery in patient 1 cells. Immunofluorescence microscopy and immunoblotting demonstrated an increase in LC3B-positive structures and LC3B-II levels, respectively, in patient 1 fibroblasts under steady-state condition. Treatment of serum-starved fibroblasts with or without bafilomycin A1 identified significantly decreased autophagic flux in patient 1 cells. Our data suggest a block at the terminal stage of autolysosome formation and/or clearance in patient fibroblasts. BNIP1 together with RAB33B and VPS16, disease genes for Smith-McCort dysplasia 2 and a multisystem disorder with short stature, respectively, highlight the importance of autophagy in skeletal development.

Novel Loss-of-Function Mutations in NPR2 Cause Acromesomelic Dysplasia, Maroteaux Type.

Acromesomelic dysplasia, Maroteaux type (AMDM) is a rare skeletal dysplasia characterized by severe disproportionate short stature, short hands and feet, normal intelligence, and facial dysmorphism. Homozygous or compound heterozygous mutations in the natriuretic peptide receptor 2 (NPR2) gene produce growth-restricted phenotypes. The current study was designed to identify and characterize NPR2 loss-of-function mutations in patients with AMDM and to explore therapeutic responses to recombinant growth hormone (rhGH). NPR2 was sequenced in two Chinese patients with AMDM via next generation sequencing, and in silico structural analysis or transcript analysis of two novel variants was performed to examine putative protein changes. rhGH treatment was started for patient 1. Three NPR2 mutations were identified in two unrelated cases: two compound heterozygous mutations c.1112G>A p.(Arg371Gln) and c.2887+2T>C in patient 1 and a homozygous mutation c.329G>A p.(Arg110His) in patient 2, yielding distinct phenotypes. RNA extracted from peripheral blood cells of patient 1 showed alternatively spliced transcripts not present in control cells. Homology modeling analyses suggested that the c.1112G>A p.(Arg371Gln) mutation disrupted the binding of NPR-B homodimer to its ligand (C-type natriuretic peptide) in the extracellular domain as a result of global allosteric effects on homodimer formation. Thus, c.2887+2T>C and c.1112G>A p.(Arg371Gln) in NPR2 were loss-of-function mutations. Furthermore, rhGH therapy in patient 1 increased the patient’s height by 0.6SDS over 15 months without adversely affecting the trunk-leg proportion. The short-term growth-promoting effect was equivalent to that reported for idiopathic short stature. Overall, our findings broadened the genotypic spectrum of NPR2 mutations in individuals with AMDM and provided insights into the efficacy of rhGH in these patients.

EP115: Two novel NPR2 variants in a patient with acromesomelic dysplasia - Maroteaux type

Acromesomelic dysplasia, Maroteaux type (AMDM) is a rare autosomal recessive skeletal dysplasia characterized by severe disproportionate short stature (adult height < 120 cm), dolichocephaly, acro- and mesomelic shortening of the limbs, short, broad fingers and flat feet. Radiographic findings include bowed radius with a short ulna, dolichocephaly, platyspondyly and narrowing of the lumbar interpedicular distances. Intelligence is unaffected. The condition is typically diagnosed at birth or in infancy, but features become more apparent over time because of the loss of linear growth. AMDM is caused by biallelic loss of function variants in the NPR2 gene which encodes the natriuretic peptide receptor-B (NPR-B). The NPR2 gene encodes a transmembrane receptor that is critical in endochondral bone formation. Forty four percent of variants in NPR2 occur in the ligand binding domain, 8% in the transmembrane domain, 26% in the protein kinase domain and 21% in the nucleotide cyclase domain. A seven-month-old was seen with clinical findings suggestive of a skeletal dysplasia. She was born at 36 weeks following a pregnancy complicated by maternal polysubstance use and poor prenatal care. Clinical findings were shortening of all limb segments, trident hands, weak grasp, and overlapping second and third toes bilaterally. Radiographic findings were shortening of all the long bones with metaphyseal flaring, short and broad metatarsals, metacarpals and phalanges also with mild metaphyseal widening, platyspondyly with mild anterior vertebral body beaking in the upper lumbar spine. Cervical CT examination revealed platyspondyly of the suboccipital vertebrae and decreased AP diameter of the spinal canal at C1 secondary to anterior bowing of the posterior arch. A multi-gene skeletal dysplasia panel identified twelve variants, including two variants in NPR2. NPR2 c.1699G>T was classified as pathogenic, causing a premature termination at amino acid 567 in the kinase homology domain of the transmembrane protein. While classified as a VUS, the c.1123G>A missense variant was predicted to cause a substitution at amino acid 375 and falls at the last nucleotide of exon 4, which is part of the consensus splice site for this exon. The patient’s mother tested positive for the pathogenic variant and negative for the VUS in NPR2. Acromesomelic dysplasia, Maroteaux type is a rare skeletal dysplasia with limited published phenotypic and molecular information available. The described patient presented a diagnostic conundrum because only one of the variants had been characterized as pathogenic. The variant of uncertain significance is located in the ligand binding domain of the NPR2 gene, in which the majority of reported variants in this gene are found. In silico algorithms predict this variant to be deleterious to the protein structure and function but these predictions have not been confirmed by functional studies. Furthermore, missense variants within the consensus splice sites commonly cause abnormal splicing. This variant is not found in population databases. While paternal samples are not available to confirm that the variants are in trans, the patient was given the diagnosis of AMDM based on her clinical presentation. Molecular analysis and clinical description of other patients with AMDM will continue to characterize disease causing variants and natural history of this rare disease.

Abstract 146: Cleidocranial dysplasia: A rare cause of severe short stature

Background: Cleidocranial dysplasia (CCD) is a rare autosomal dominant skeletal dysplasia due to Runx 2 mutation with 1:1,000,000 incidence, characterized by hypoplastic clavicles, delayed closure of the cranial sutures, dental abnormalities, and short stature.Aims and Objectives: We report a case of 11year old boy presenting with short stature and classical features of cleidocranial dysplasia.Results: A 11 year boy with poor height gain since 2 years of age, was found to have severe disproportionate short stature with deciduous teeth, supernumerary teeth, midfacial hypoplasia, flattened nasal bridge, hypertelorism, high arched palate, short thumbs, clinodactyly and anterior apposition of shoulders. Skeletal survey confirmed these findings, along with Brachycephaly with open fontanelles, clavicular hypoplasia, bell shaped thorax, hypoplasia of the pelvis with widened symphysis pubis, coxa vara, pseudoepiphysis of 2nd metacarpal and severe dental anomalies.Conclusion: A thorough history and examination with radiological support will help in timely diagnosis of CCD in children and adequate treatment.

Disease-specific complications and multidisciplinary interventions in achondroplasia.

Achondroplasia (ACH) is the most common skeletal dysplasia and characterized by a disproportionate short stature, macrocephaly with frontal bossing, exaggerated lumbar lordosis, and trident hands. It is induced by activated mutations in the fibroblast growth factor receptor 3 (FGFR3) gene. In addition to short stature, patients with ACH have a high prevalence of medical complications, including upper airway obstructive apnea, increased mortality, foramen magnum stenosis, hydrocephalus, developmental delay, recurrent ear infections, genu varum, obesity, and spinal canal stenosis, throughout their whole life. Several investigational drugs that modulate abnormal FGFR3 signaling have recently emerged, vosoritide being the most developed. This review presents the different disease-specific complications of ACH occurring in neonates, infants, childhood, adolescent, and adults and reports the current multidisciplinary interventions for these various complications. Moreover, we propose treatment strategies for children with ACH from the perspective of quality of life in adulthood.

POSC186 Higher Rates of Complications and Health-Care Resource Utilisation in Achondroplasia Compared to the General Population: A Matched Cohort Study Using the Cprd-HES Database

Achondroplasia (ACH) is a rare skeletal dysplasia condition, resulting in disproportionate short stature and multiple complications. We aimed to estimate disease burden and health-care resource use (HCRU) in ACH patients compared to general population controls.

Uncovering pathways regulating chondrogenic differentiation of CHH fibroblasts

Mutations in the non-coding snoRNA component of mitochondrial RNA processing endoribonuclease (RMRP) are the cause of cartilage-hair hypoplasia (CHH). CHH is a rare form of metaphyseal chondrodysplasia characterized by disproportionate short stature and abnormal growth plate development. The process of chondrogenic differentiation within growth plates of long bones is vital for longitudinal bone growth. However, molecular mechanisms behind impaired skeletal development in CHH patients remain unclear. We employed a transdifferentiation model (FDC) combined with whole transcriptome analysis to investigate the chondrogenic transdifferentiation capacity of CHH fibroblasts and to examine pathway regulation in CHH cells during chondrogenic differentiation. We established that the FDC transdifferentiation model is a relevant in vitro model of chondrogenic differentiation, with an emphasis on the terminal differentiation phase, which is crucial for longitudinal bone growth. We demonstrated that CHH fibroblasts are capable of transdifferentiating into chondrocyte-like cells, and show a reduced commitment to terminal differentiation. We also found a number of key factors of BMP, FGF, and IGF-1 signalling axes to be significantly upregulated in CHH cells during the chondrogenic transdifferentiation. Our results support postulated conclusions that RMRP has pleiotropic functions and profoundly affects multiple aspects of cell fate and signalling. Our findings shed light on the consequences of pathological CHH mutations in snoRNA RMRP during chondrogenic differentiation and the relevance and roles of non-coding RNAs in genetic diseases in general.

Orthopedic concerns of a child with short stature.

Pediatric short stature poses severe concerns to the patient, parents, and physicians. Management for pediatric short stature is still widely debated due to heterogenous etiological factors and treatment options. This review will address the approach to pediatric short stature, commonly within the subset of skeletal dysplasia resulting in disproportionate short stature. The following will be discussed: the etiology, clinical, and radiological evaluations, and management for pediatric short stature. Early recognition of short stature and appropriate referrals is shown to benefit the patient and reduce parental concern. A multidisciplinary team, comprising an orthopedic surgeon, is fundamental to provide holistic care and ensure overall good quality of life. Advancements in clinical diagnostic tools and diversified treatment modalities today provides optimism in managing pediatric short stature. Skeletal dysplasia can be treated with good prognosis if diagnosed and managed early. Thorough clinical, radiological, laboratory, and even genetic investigations are important to differentiate and manage various types of skeletal dysplasia. Our review will provide a comprehensive and up-to-date approach to skeletal dysplasia for pediatric orthopedic surgeons, and indications for physicians to refer patients with suspected short stature to pediatric orthopedic surgeons.

Clinical, Biochemical, Radiological, Genetic and Therapeutic Analysis of Patients with COMP Gene Variants.

Pseudoachondroplasia (PSACH) and multiple epiphyseal dysplasia type 1 (MED1) are two rare skeletal disorders caused by cartilage oligomeric matrix protein (COMP) variants. This study aims to analyze the genotype and phenotype of patients with COMP variants. Clinical information for 14 probands was collected; DNA was extracted from blood for COMP variant detection. Clinical manifestations and radiology scoring systems were established to evaluate the severity of each patient's condition. Serum COMP levels in PSACH patients and healthy subjects were measured. Thirty-nine patients were included, along with 12 PSACH probands and two MED1 probands. Disproportionate short stature, waddling gait, early-onset osteoarthritis and skeletal deformities were the most common features. The height Z-score of PSACH patients correlated negatively with age at evaluation (r = - 0.603, p = 0.01) and the clinical manifestation score (r = - 0.556, p = 0.039). Over 50% of the PSACH patients were overweight/obese. The median serum COMP level in PSACH patients was 16.75ng/ml, which was significantly lower than that in healthy controls (98.53ng/ml; p < 0.001). The condition of MED1 patients was better than that of PSACH patients. Four novel variants of COMP were detected: c.874T>C, c.1123_1134del, c.1531G>A, and c.1576G>T. Height Z-scores and serum COMP levels were significantly lower in patients carrying mutations located in calmodulin-like domains 6, 7, and 8. As the two phenotypes overlap to different degrees, PSACH and MED1 are suggested to combine to produce "spondyloepiphyseal dysplasia, COMP type". Clinical manifestations and radiology scoring systems, serum COMP levels and genotype are important for evaluating patient condition severity.

Emerging therapies for Achondroplasia: changing the rules of the game

ABSTRACT Introduction Achondroplasia is the most common genetic cause of disproportionate short stature, affecting over 360,000 individuals. Serious complications contributing to significant morbidity in affected individuals include cranio-cervical junction compression and obstructive sleep apnea. Current clinically available treatments are predominantly symptomatic and associated with variable outcomes. We summarize the new precision investigational products that are currently in Phase 2 and Phase 3 clinical trials for the treatment of individuals with achondroplasia. Areas covered Fibroblast growth factor receptor 3 (FGFR3), a membrane-spanning tyrosine kinase receptor, binds various fibroblast growth factors (FGF) to regulate the normal process of endochondral bone growth. Gain of FGFR3 function in individuals with achondroplasia results in inhibition of normal endochondral ossification. A greater understanding of these molecular pathways through animal models has led to the development of several targeted therapies being tested in children, which we discuss in this review. Expert opinion The last decade has been game-changing in terms of new precision therapies for children with achondroplasia that have the potential to fundamentally change the natural history of this condition. The next decade will see how these therapies compare, if they might be used in combination, and evaluate the balance of their long-term benefits and harms.

Etiological profile of short stature in rural Rajasthan

Background: Short stature is one of the most common referrals to pediatric endocrinology clinics. Approximately 3% of children in any population are found to be short. Aim: This study aims to determine the etiology of short stature and their frequency of occurrence in 2–18 years old rural pediatric population and to classify the patients with short stature using anthropometric measurements. Materials and Methods: A total of 400 patients (age: 2–18 years) were diagnosed with short stature and admitted in pediatric ward. After meticulous history collection and complete physical examination, relevant investigations were performed in all the study subjects. Appropriate statistical analysis was carried out with the collected data. Results: Out of 400 study subjects, 70.50% were boys (male: female=2.33:1). Majority (n=241, 60.5%) of the affected children were in the age group of 2–&lt;6 years and 7–&lt;10 years. Of the 400 study subjects, 95% of cases (n=380) were classified as having proportionate short stature and the rest (n=20, 5%) had disproportionate short stature. Undernutrition (n=117, 29.25%) and familial short stature (n=90, 22.50%) were the leading causes of short stature. Conclusion: The current study helped to determine the etiological profile of short stature in children of adjoining rural population and in devising appropriate strategies for management and prevention.