Severe Short Stature Research Articles

Clinical Characterization of Michelin Tire Baby Syndrome: A Case Report Highlighting Severe Short Stature

Clinical Characterization of Michelin Tire Baby Syndrome: A Case Report Highlighting Severe Short Stature

7140 Assessing Bone Mineral Density and Cortical Geometry Using High-resolution Peripheral Quantitative Computed Tomography and Dual Energy X-ray Absorptiometry in Pediatric Survivors of High-risk Neuroblastoma with Growth Failure

Abstract Disclosure: S. Gera: None. M. Guo: None. N. Pollock: None. I. Hampton: None. M. Song: None. D. Weber: None. M. Denburg: None. S. Mostoufi-Moab: None. Introduction: Survival of children with high-risk neuroblastoma (HR-NBL) has increased with multimodal therapy. Cis-retinoic acid (cis-RA), cornerstone of HR-NBL therapy, can cause osteoporosis and premature physeal closure, posing a threat to skeletal structure. HR-NBL survivors demonstrate profound growth failure. DXA measures areal bone mineral density (aBMD). DXA is confounded by short stature and fails to distinguish between trabecular and cortical bone. We previously reported no significant difference in height-per-age adjusted aBMD-Z in HR-NBL survivors compared to healthy controls[1]. However, aBMD-Z in severe short stature may attenuate bone density deficits. High-resolution peripheral quantitative computed tomography (HRpQCT) yields 3D measures of volumetric BMD and bone architecture. Objectives: Assess volumetric BMD (vBMD) and cortical structure using distal tibia HRpQCT and leg lean mass by DXA in HR-NBL survivors compared to healthy controls in a cross-sectional study. Methods: We prospectively enrolled 20 HR-NBL survivors (median age 12.2 yrs, range 9.5 to 15.8, 7 female) treated with cis-RA (median age 2.6 yrs at start of therapy, range 0.3-9.1), and 20 age-, sex-, and race-matched healthy controls. We assessed leg lean mass adjusted for leg length by DXA. For HRpQCT, we compared tibia length (cm), cortical and trabecular vBMD (mg HA/cm3), geometry parameters (cortical and trabecular area [mm2]), and structural parameters (cortical thickness [μm] and porosity, trabecular number [mm-[1]] and separation [μm]). Outcomes were compared using Student’s t-test or Mann-Whitney U test. Linear regression models assessed difference in outcomes of bone microarchitecture and leg lean mass between both groups. Results: Compared to controls, tibia length was significantly shorter in HR-NBL survivors (32.3 ± 0.8 vs. 35.7 ± 0.6, P<0.005). HR-NBL survivors demonstrated lower cortical area (187.6 ± 43.8 vs. 218.7 ± 42.3, P<0.05), cortical perimeter (62.4 ± 7.71 vs. 69.5 ± 8.1, P<0.01), and leg lean mass Z-score (-1.47 ± 1.34 vs. -0.20 ± 0.84, P<0.001) compared to controls. Cortical geometry deficits were explained by muscle deficits (P<0.001). Trabecular area, BMC, areal and volumetric BMD, and measures of bone structure were not significantly different in HR-NBL survivors compared to controls. IGF-1 and 25-OH D levels had no significant effects on DXA or HRpQCT parameters. Conclusion: Bone density is not severely impacted in HR-NBL survivors. Muscle deficits persist years after treatment and explain cortical geometry deficits. HRpQCT substantiates prior DXA evaluation in HR-NBL survivors with significant short stature, demonstrating preserved bone density and structure. 1.Guo et al. Sarcopenia and preserved bone mineral density in pediatric survivors of high-risk neuroblastoma with growth failure. J Cachexia Sarcopenia Muscle. 2021 Aug;12(4):1024-1033. Presentation: 6/3/2024

6369 Weiss-Kruszka Syndrome and Growth Hormone Deficiency, Adrenal Insufficiency, and Morbid Obesity

Abstract Disclosure: T. Falcon-Rodriguez: None. N. Solano: None. A. Diaz: None. Background: Weiss-Kruszka syndrome (WKSA) is a rare autosomal dominant genetic disorder caused by heterozygous loss-of-function variants in the ZNF462 gene. Individuals affected by this condition exhibit distinctive craniofacial features, ptosis, dysgenesis of the corpus callosum, hearing loss, intellectual disability, and hypotonia. There is one other case report that described a boy with empty sella syndrome with growth hormone deficiency and delayed puberty. Case Presentation: We present the case of a 15-year-old boy who initially came under the care of endocrinology at age 9 due to severe obesity and short stature. Past medical history included ADHD (for which he was on stimulants since age 5), microcephaly, VUR, asthma, and developmental delay. He grew along the 2nd percentile for height from the ages of 6 and 13, after which his growth velocity notably decelerated. His initial bone age at 9 years old was advanced by 3 years. His BMI had exceeded the 99th percentile since age 3. His family history was relevant for maternal type 1 diabetes mellitus, paternal height of 165 cm, and maternal height of 160 cm. Upon physical examination, notable findings included short stature, severe obesity, a low anterior hairline, arched eyebrows, upslanted palpebral fissures, low-set ears, a tubular and short nasal bridge, and an exaggerated cupid's bow. At age 9, the patient was diagnosed with growth hormone (GH) deficiency following a clonidine and glucagon stimulation test, with a GH peak of 1.9 ng/mL (normal >7 ng/mL). Additionally, he was diagnosed with adrenal insufficiency (cortisol peak of 5 ug/dL, after 250 mcg of cosyntropin). A brain/sella MRI revealed a hypoplastic pituitary gland. Subsequently, hydrocortisone replacement was initiated at a dose of 6 mg/m2/day, and GH treatment at a weekly dose of 0.3 mg/kg. Despite treatment with growth hormone and IGF-1 levels on the upper side of the normal range, his growth velocity did not improve significantly. He reached his peak adult height of 150 cm at age 15. His BMI had consistently been at the 99th percentile. According to his mother, he did not have issues with satiety, and his portion sizes were considered normal. He did not consume fast foods or sugary drinks, and his level of physical activity was suboptimal. Whole Exome Sequencing identified a heterozygous de novo pathogenic variant in the ZNF462 gene, specificallyc.2664 C>A, p.(C888*) (NM_021224.4), consistent with the diagnosis of Weiss-Kruszka syndrome (OMIM # 618619). Conclusion: We present, to our knowledge, the first report of morbid obesity and central adrenal insufficiency in a child with WSKA. GH deficiency had been previously reported in 1 patient with WSKA. The finding of a hypoplastic pituitary gland supports the diagnosis of GH deficiency and central adrenal insufficiency. Presentation: 6/3/2024

An unusual case of 17-hydroxylase deficiency presenting with short stature

17α-Hydroxylase and 17,20-lyase are enzymes encoded by the CYP17A1 gene and are necessary for the production of cortisol and sex steroids. Females with 17α-hydroxylase deficiency usually present with primary amenorrhea and delayed puberty accompanied by hypertension and electrolyte imbalance. Here, we report the case of a 14-year-old female patient who presented with severe short stature and delayed puberty without any complaint suggestive of 17-hydroxylase enzyme deficiency. Laboratory test results showed low cortisol and dehydroepiandrosterone sulfate (DHEA-S) along with high luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Turner syndrome was excluded after genetic analysis showed a 46,XX karyotype, and 17α-hydroxylase deficiency was diagnosed by detecting a c.1319G>A (p.Arg440His) variation/alternation in the patient's CYP17A1 gene.

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

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. 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. 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. 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.

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. 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). 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. 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.

The prevalence of celiac disease among children with short stature

Background and objectives: The most important characters of children are growth and development. There are many causes of short stature. Among causes of short stature celiac disease is the important reversible cause. Celiac disease can be diagnosed serologically or/and duodenal biopsy according to the level of serological tests or/and symptoms. The main objective of the study was to find the relation between having high tissue transglutaminase antibody and short stature Methods: This is a cross sectional study. From March 2021 to March 2022, consecutive sampling from of 79 children who presented to Helina center in Erbil city and Hawler teaching hospital (department of endocrinology) complaining to have short stature and recorded as short child. Tissue transglutaminase antibody were sent for all patients, and duodenal biopsy for selected cases were done. Result: Seventy-nine children with short stature were included in the study. Their mean age (SD) was 8.3 (3.3) years. The median was 8 years, and the age range was 1.1-16 years. More than half (54.4%) of the sample were aged 5-9 years, and 42 patients (53.2%) were females. The prevalence of celiac disease among children with short stature in our study was 13.9%, which is statistically is significant. The majority (69.6%) of the children had severe short stature (less than -2 Z score), and the rest had acceptable Z score. Conclusion: In conclusion, celiac disease should be considered in the differential diagnosis of patient who presents with short stature as it is not uncommon in our community. Sending for non-invasive investigations for diagnosing celiac disease is easier and simpler than other invasive procedures.

A Clinical Trial of High Dose Growth Hormone in a Patient with a Dominant Negative Growth Hormone Receptor Mutation.

Rare patients with short stature and growth hormone (GH) resistance have dominant-negative variants in the GH receptor. We describe a patient with GH resistance due to elevated levels of GH binding protein and demonstrate the potential for a precision medicine intervention. To determine whether high dose GH can overcome GH resistance in this specific patient resulting in normal IGF-1 levels and improved growth rates. Single patient trial of ascending doses of GH followed by dose stable phase; total 12 months of treatment. Patient has a heterozygous variant in GH receptor resulting in elevated levels of GH binding protein manifesting as GH resistance and severe short stature. Daily subcutaneous GH starting at 50 micrograms/kg/day and escalating to 250 micrograms/kg/day until goal IGF-1 achieved. Subject continued 250 micrograms/kg/day for a total treatment duration of 12 months. The primary outcome measure was the dose of GH required to achieve an IGF-1 level above the mid-point of the normal range. Secondary endpoints included height velocity and the change in height SDS during the 1st year of treatment. A dose of GH of 250 micrograms/kg/day achieved the target IGF-1 level. The patient's annualized height velocity was 8.7 cm/year, an increase of 3.4 cm/year from baseline, resulting in a 0.81 SD gain in height. A precision medicine approach of extremely high dose GH was able to overcome GH resistance in a patient with a dominant-negative variant in the GH receptor resulting in elevated GH binding protein levels.

Clinical phenotype and genetic analysis of six Chinese patients affected with Acromicric dysplasia due to variants of FBN1 gene

To retrospectively analyze the clinical and genetic characteristics of six patients with Acromicric dysplasia due to variants of the FBN1 gene. Six patients who had visited the Affiliated Hospital of Qingdao University between February 2018 and October 2020 were selected as the study subjects. Clinical data of the patients were collected. High-throughput sequencing was carried out. And candidate variants were verified by Sanger sequencing. All of the six patients had presented with severe short stature (< 3s), brachydactyly, short and broad hands and feet. Other manifestations included joint stiffness, facial dysmorphism, delayed bone age, liver enlargement, coracoid femoral head, and lumbar lordosis. Genetic testing revealed that all had harbored heterozygous variants of the FBN1 gene. Patient 1 had harbored a c.5183C>T (p.A1728V) missense variant in exon 42, which had derived from his father (patient 2). Patient 3 had harbored a c.5284G>A (p.G1762S) missense variant in exon 43, which had derived from her mother (patient 4). Patient 5 had harbored a c.5156G>T (p.C1719F) missense variant in exon 42, which was de novo in origin. Patient 6 had harbored a c.5272G>T (p.D1758Y) missense variant in exon 43, which was also de novo in origin. The variants carried by patients 1, 3 and 6 were known to be pathogenic. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the FBN1: c.5156G>T was rated as a pathogenic variant (PS2+PM1+PM2_Supporting +PM5+PP3). All of the six patients had severe short stature and a variety of other clinical manifestations, which may be attributed to the variants of the FBN1 gene.

Promising horizons in achondroplasia along with the development of new drugs.

Achondroplasia (ACH) is a representative skeletal disorder characterized by rhizomelic shortened limbs and short stature. ACH is classified as belonging to the fibroblast growth factor receptor 3 (FGFR3) group. The downstream signal transduction of FGFR3 consists of STAT1 and RAS/RAF/MEK/ERK pathways. The mutant FGFR3 found in ACH is continuously phosphorylated and activates downstream signals, resulting in abnormal proliferation and differentiation of chondrocytes in the growth plate and cranial base synchondrosis. A patient registry has been developed and has contributed to revealing the natural history of ACH patients. Concerning the short stature, the adult height of ACH patients ranges between 126.7-135.2 cm for men and 119.9-125.5 cm for women in many countries. Along with severe short stature, foramen magnum stenosis and spinal canal stenosis are major complications: the former leads to sleep apnea, breathing disorders, myelopathy, hydrocephalus, and sudden death, and the latter causes pain in the extremities, numbness, muscle weakness, movement disorders, intermittent claudication, and bladder-rectal disorders. Growth hormone treatment is available for ACH only in Japan. However, the effect of the treatment on adult height is not satisfactory. Recently, the neutral endopeptidase-resistant CNP analogue vosoritide has been approved as a new drug for ACH. Additionally in development are a tyrosine kinase inhibitor, a soluble FGFR3, an antibody against FGFR3, meclizine, and the FGF2-aptamer. New drugs will bring a brighter future for patients with ACH.

Bi-allelic variants in CEP295 cause Seckel-like syndrome presenting with primary microcephaly, developmental delay, intellectual disability, short stature, craniofacial and digital abnormalities

Pathogenic variants in the centrosome protein (CEP) family have been implicated in primary microcephaly, Seckel syndrome, and classical ciliopathies. However, most CEP genes remain unlinked to specific Mendelian genetic diseases in humans. We sought to explore the roles of CEP295 in human pathology. Whole-exome sequencing was performed to screen for pathogenic variants in patients with severe microcephaly. Patient-derived fibroblasts and CEP295-depleted U2OS and RPE1 cells were used to clarify the underlying pathomechanisms, including centriole/centrosome development, cell cycle and proliferation changes, and ciliogenesis. Complementary experiments using CEP295 mRNA were performed to determine the pathogenicity of the identified missense variant. Here, we report bi-allelic variants of CEP295 in four children from two unrelated families, characterized by severe primary microcephaly, short stature, developmental delay, intellectual disability, facial deformities, and abnormalities of fingers and toes, suggesting a Seckel-like syndrome. Mechanistically, depletion of CEP295 resulted in a decrease in the numbers of centrioles and centrosomes and triggered p53-dependent G1 cell cycle arrest. Moreover, loss of CEP295 causes extensive primary ciliary defects in both patient-derived fibroblasts and RPE1 cells. The results from complementary experiments revealed that the wild-type CEP295, but not the mutant protein, can correct the developmental defects of the centrosome/centriole and cilia in the patient-derived skin fibroblasts. This study reports CEP295 as a causative gene of the syndromic microcephaly phenotype in humans. Our study also demonstrates that defects in CEP295 result in primary ciliary defects. A full list of funding bodies that contributed to this study can be found under "Acknowledgments."

Clinical, genetic and structural delineation of RPL13-related spondyloepimetaphyseal dysplasia suggest extra-ribosomal functions of eL13

Spondyloepimetaphyseal dysplasia with severe short stature, RPL13-related (SEMD-RPL13), MIM#618728), is a rare autosomal dominant disorder characterized by short stature and skeletal changes such as mild spondylar and epimetaphyseal dysplasia affecting primarily the lower limbs. The genetic cause was first reported in 2019 by Le Caignec et al., and six disease-causing variants in the gene coding for a ribosomal protein, RPL13 (NM_000977.3) have been identified to date. This study presents clinical and radiographic data from 12 affected individuals aged 2–64 years from seven unrelated families, showing highly variable manifestations. The affected individuals showed a range from mild to severe short stature, retaining the same radiographic pattern of spondylar- and epi-metaphyseal dysplasia, but with varying severity of the hip and knee deformities. Two new missense variants, c.548 G>A, p.(Arg183His) and c.569 G>T, p.(Arg190Leu), and a previously known splice variant c.477+1G>A were identified, confirming mutational clustering in a highly specific RNA binding motif. Structural analysis and interpretation of the variants’ impact on the protein suggests that disruption of extra-ribosomal functions of the protein through binding of mRNA may play a role in the skeletal phenotype of SEMD-RPL13. In addition, we present gonadal and somatic mosaicism for the condition.

Two new patients with acromesomelic dysplasia, PRKG2 type-identification and characterization of the first missense variant.

Acromesomelic dysplasia, PRKG2 type (AMDP, MIM 619636), is an extremely rare autosomal recessive skeletal dysplasia characterized by severe disproportionate short stature presenting with acromesomelia, mild metaphyseal widening of the long bones and mild spondylar dysplasia. To date, only four variants have been reported; one nonsense, one splice-site, and two frameshifts in five AMDP families. Here, we report the first missense variant and a second splice-site variant in PRKG2 in two patients with clinical and radiological features of acromesomelic dysplasia. Furthermore, functional studies of the novel missense variant, p.Val470Gly, revealed that it was unable to down-regulate FGF2-induced MAPK signaling and, thus, would be predicted to cause growth delay. Hence, this report expands the mutational spectrum in skeletal dysplasias associated with PRKG2 variants. In addition, we propose recognizable facial features with acromesomelic dysplasia, PRKG2 type.

Growth charts in DYRK1A syndrome.

DYRK1A Syndrome (OMIM #614104) is caused by pathogenic variations in the DYRK1A gene located on 21q22. Haploinsufficiency of DYRK1A causes a syndrome with global psychomotor delay and intellectual disability. Low birth weight, growth restriction with feeding difficulties, stature insufficiency, and microcephaly are frequently reported. This study aims to create specific growth charts for individuals with DYRK1A Syndrome and identify parameters for size prognosis. Growth parameters were obtained for 92 individuals with DYRK1A Syndrome (49 males vs. 43 females). The data were obtained from pediatric records, parent reporting, and scientific literature. Growth charts for height, weight, body mass index (BMI), and occipitofrontal circumference (OFC) were generated using generalized additive models through R package gamlss. The growth curves include height, weight, and OFC measurements for patients aged 0-5 years. In accordance with the literature, the charts show that individuals are more likely to present intrauterine growth restriction with low birth weight and microcephaly. The growth is then characterized by severe microcephaly, low weight, and short stature. This study proposes growth charts for widespread use in the management of patients with DYRK1A syndrome.

Clinico-radiological correlation of pituitary stalk interruption syndrome in children with growth hormone deficiency.

To analyze the clinical, hormonal, and radiological characteristics of Pituitary stalk interruption syndrome (PSIS) in children with growth hormone deficiency (GHD). This is a prospective cross-sectional study, conducted over a period of three years in a short stature clinic of tertiary care referral hospital. 57 severe short stature children with proven GHD were included in the study. Among 57 children with GHD, 14 (24%) were diagnosed as PSIS. The mean age at diagnosis was 11.8 ± 2.6years. The male to female ratio was 2.5:1. Nine (64%) children had multiple pituitary hormone deficiency (MPHD) and 5 (36%) had isolated growth hormone deficiency (IGHD). In spite of absent or ectopic posterior pituitary (EPP)in Magnetic Resonance Imaging (MRI) of PSIS cohorts, only one had Arginine vasopressin (AVP) deficiency. EPP was seen near median eminence in 6 (44%), elsewhere in 4 (28%), and absent in 4 (28%)children. The height gain following growth hormone therapy was better in PSIS cohorts as compared to non-PSIS. Male gender, breech presentation, external congenital anomalies like cryptorchidism, midline defects and nystagmus were more common in children with PSIS. MPHD were more frequently seen in PSIS whereas IGHD in non-PSIS cohort. AVP deficiency is very rare in PSIS despite of absent or ectopic posterior pituitary in MRI. High index of clinical suspicion in all severe short stature may lead to early diagnosis and prompt initiation of growth hormone treatment for better outcome.

Molecular and phenotypic spectrum of cardio-facio-cutaneous syndrome in Chinese patients

BackgroundCardio-facio-cutaneous (CFC) syndrome is a RASopathy subtype that presents with unique craniofacial dysmorphology, congenital heart disease, dermatologic abnormalities, growth retardation, and intellectual disability. This study describes the phenotypic spectrum of CFC in China and its association with CFC syndrome gene variants.ResultsTwenty Chinese CFC patients, aged 0.6–9.5 years old, were included in this study and their clinical phenotypic spectrum was compared with that of 186 patients with CFC from non-Chinese ethnicities. All 20 Chinese patients with CFC carried de novo heterozygous BRAF, MAP2K1, and MAP2K2 variants. Two novel variants were detected and consistently predicted to be deleterious using bioinformatic tools. The clinical features of CFC in the Chinese patients included hypertrophic cardiomyopathy (2/20, 10%), pulmonary valve stenosis (2/20, 10%), curly or sparse hair (7/20, 35%), epilepsy (1/20, 5%), and hypotonia (10/20, 50%); these features were less frequently observed in Chinese patients than non-Chinese patients (p < 0.05). In contrast, feeding difficulties (19/20, 95%) were more frequently observed in the Chinese patients. Absent eyebrows and severe short stature were more common in patients with BRAF variants than in those with MAP2K1/2 variants. Facial recognition software was used to recognize most CFC patients using artificial intelligence.ConclusionThis study identified novel and common variants in our cohort of 20 Chinese patients with CFC. We uncovered differences in clinical features between Chinese and non-Chinese patients and detected genotype–phenotype correlations among the BRAF and MAP2K1/2 variant subgroups. This is the largest cohort of Chinese CFC patients to our knowledge, providing new insights into a subtype of RASopathy.

Clinical and genetic evaluation of children with short stature of unknown origin

BackgroundShort stature is a common human trait. More severe and/or associated short stature is usually part of the presentation of a syndrome and may be a monogenic disease. The present study aimed to identify the genetic etiology of children with short stature of unknown origin.MethodsA total of 232 children with short stature of unknown origin from March 2013 to May 2020 were enrolled in this study. Whole exome sequencing (WES) was performed for the enrolled patients to determine the underlying genetic etiology.ResultsWe identified pathogenic or likely pathogenic genetic variants in 18 (7.8%) patients. All of these variants were located in genes known to be associated with growth disorders. Five of the genes are associated with paracrine signaling or cartilage extracellular matrix in the growth plate, including NPR2 (N = 1), ACAN (N = 1), CASR (N = 1), COMP (N = 1) and FBN1 (N = 1). Two of the genes are involved in the RAS/MAPK pathway, namely, PTPN11 (N = 6) and NF1 (N = 1). Two genes are associated with the abnormal growth hormone-insulin-like growth factor 1 (GH-IGF1) axis, including GH1 (N = 1) and IGF1R (N = 1). Two mutations are located in PROKR2, which is associated with gonadotropin-releasing hormone deficiency. Mutations were found in the remaining two patients in genes with miscellaneous mechanisms: ANKRD11 (N = 1) and ARID1A (N = 1).ConclusionsThe present study identified pathogenic or likely pathogenic genetic variants in eighteen of the 232 patients (7.8%) with short stature of unknown origin. Our findings suggest that in the absence of prominent malformation, genetic defects in hormones, paracrine factors, and matrix molecules may be the causal factors for this group of patients. Early genetic testing is necessary for accurate diagnosis and precision treatment.

Uncommon clinical features of juvenile primary hypothyroidism

This case study presents an 18-year-old boy with severe short stature and distinct physical features, including facial abnormalities, skeletal deformities, and intellectual impairment. Further investigations revealed hypothyroidism, autoimmune thyroiditis, and delayed bone age. Treatment with levothyroxine replacement therapy was initiated. The study highlights the importance of detection and management of hypothyroidism in individuals with short stature and associated features.

A novel de novo variant in CASK causes a severe neurodevelopmental disorder that masks the phenotype of a novel de novo variant in EEF2.

We report a 9-year-old Spanish boy with severe psychomotor developmental delay, short stature, microcephaly and abnormalities of the brain morphology, including cerebellar atrophy. Whole-exome sequencing (WES) uncovered two novel de novo variants, a hemizygous variant in CASK (Calcium/Calmodulin Dependent Serine Protein Kinase) and a heterozygous variant in EEF2 (Eukaryotic Translation Elongation Factor 2). CASK gene encodes the peripheral plasma membrane protein CASK that is a scaffold protein located at the synapses in the brain. The c.2506-6 A > G CASK variant induced two alternative splicing events that account for the 80% of the total transcripts, which are likely to be degraded by NMD. Pathogenic variants in CASK have been associated with severe neurological disorders such as mental retardation with or without nystagmus also called FG syndrome 4 (FGS4), and intellectual developmental disorder with microcephaly and pontine and cerebellar hypoplasia (MICPCH). Heterozygous variants in EEF2, which encodes the elongation factor 2 (eEF2), have been associated to Spinocerebellar ataxia 26 (SCA26) and more recently to a childhood-onset neurodevelopmental disorder with benign external hydrocephalus. The yeast model system used to investigate the functional consequences of the c.34 A > G EEF2 variant supported its pathogenicity by demonstrating it affects translational fidelity. In conclusion, the phenotype associated with the CASK variant is more severe and masks the milder phenotype of EEF2 variant.

IPSC reprogramming of two patients with spondyloepiphyseal dysplasia congenita (SEDC)

Spondyloepiphyseal dysplasia congenita (SEDC) is a severe non-lethal type 2 collagenopathy caused by pathogenic variants in the COL2A1 gene, which encodes the alpha-1 chain of type II collagen. SEDC is clinically characterized by severe short stature, degenerative joint disease, hearing impairment, orofacial anomalies and ocular manifestations. To study and therapeutically target the underlying disease mechanisms, human iPSC-chondrocytes are considered highly suitable as they have been shown to exhibit several key features of skeletal dysplasias. Prior to creating iPSC-chondrocytes, peripheral blood mononuclear cells of two male SEDC patients, carrying the p.Gly1107Arg and p.Gly408Asp pathogenic variants, respectively, were successfully reprogrammed into iPSCs using the CytoTune™-iPS 2.0 Sendai Kit (Invitrogen).