Residual levels, phase distributions, and human health risks of OCPs in the middle reach of the Huai River, China.

Are the residues of organochlorine pesticides (OCPs) in freshwater in China still of concern after prohibition and restriction for decades? The scarcity of monitoring data on OCPs in freshwater in China over the past few years has hampered understanding of this issue. In this study, water and suspended particulate matter (SPM) samples were collected from the middle reach of the Huai River for OCP analyses. Residues of ∑OCPs in water and SPM ranged from ND to 8.6 ng L-1 and 0.50 to 179 ng L-1, with mean concentrations of 1.7 ± 1.3 ng L-1 and 6.1 ± 31 ng L-1, respectively. ∑HCHs (α-, ß-, γ-, and δ-HCH) and ∑HEPTs (heptachlor and heptachlor epoxide) were the most predominant pesticides in the dissolved phase and SPM, respectively, accounting for 43 ± 35% and 27 ± 29% of ∑OCPs. HCHs and heptachlor epoxide mainly existed in the dissolved phase, while heptachlor mainly existed in SPM. The isomeric composition pattern of HCHs in water differed from that in SPM. Briefly, ß-HCH dominated in water, while δ-HCH dominated in SPM. However, the composition pattern of DDT and its metabolites in water was similar to that in SPM. o,p'-DDD and p,p'-DDE dominated in both water and SPM. The ratios of α-/γ-HCH and (DDD + DDE)/DDTs indicated that HCHs and DDTs were mainly derived from historical residues. Risk assessments indicated that OCPs may not pose carcinogenic and non-carcinogenic risks to residents.

Growth reference charts for children with hypochondroplasia.

Hypochondroplasia (HCH) is a rare skeletal dysplasia causing mild short stature. There is a paucity of growth reference charts for this population. Anthropometric data were collected to generate height, weight, and head circumference (HC) growth reference charts for children with a diagnosis of HCH. Mixed longitudinal anthropometric data and genetic analysis results were collected from 14 European specialized skeletal dysplasia centers. Growth charts were generated using Generalized Additive Models for Location, Scale, and Shape. Measurements for height (983), weight (896), and HC (389) were collected from 188 (79 female) children with a diagnosis of HCH aged 0-18 years. Of the 84 children who underwent genetic testing, a pathogenic variant in FGFR3 was identified in 92% (77). The data were used to generate growth references for height, weight, and HC, plotted as charts with seven centiles from 2nd to 98th, for ages 0-4 and 0-16 years. HCH-specific growth charts are important in the clinical care of these children. They help to identify if other comorbidities are present that affect growth and development and serve as an important benchmark for any prospective interventional research studies and trials.

Prophylactic Intramedullary Rodding After Femoral Lengthening in Patients With Achondroplasia and Hypochondroplasia.

BACKGROUND: Femoral fracture after femoral lengthening in patients with achondroplasia and hypochondroplasia is a frequent complication, occurring in up to 30%. The purpose of this study is to demonstrate the effectiveness of prophylactic intramedullary rodding in preventing this complication. METHODS: Multicenter retrospective study involving 86 femoral lengthening procedures in 43 patients with achondroplasia or hypochondroplasia. Forty-two femora (21 patients) were prophylactically managed with intramedullary Rush rodding after external fixation removal (11 females and 10 males, mean age 14.6 years) compared with 44 femora (22 patients) without prophylactic intramedullary rodding (13 females and 9 males, mean age 15.2 years). The mean amount of lengthening in the rodding group was 13.3 cm (52.6%) with an External Fixation Index of 25.8 days/cm; in patients without rodding was 14.3 cm (61.5%) and 24.5 days/cm, respectively. RESULTS: Seven cases (15.9%) without rodding developed fractures. Four of them required surgical correction due to displacement or shortening. Only 1 patient (2.4%) had fracture of the femur after prophylactic rodding, and surgery was not required. The incidence of femur fracture was significantly lower in the prophylactic rodding group compared with the nonrodding group (2.4% vs. 15.9%, respectively; P =0.034). There were no cases of infection or avascular necrosis. CONCLUSIONS: Prophylactic intramedullary rodding is a safe and effective method for preventing femoral fractures after femoral lengthening in patients with achondroplasia or hypochondroplasia. LEVEL OF EVIDENCE: Level III-a retrospective comparative study.

Disfagia orofaríngea y malformaciones anatómicas / Oropharyngeal dysphagia and anatomical malformations

Introducción: La disfagia orofaríngea o dificultad para la deglución puede ser causada por anomalías anatómicas, incluyendo malformaciones óseas cervicales. La evaluación integral y el tratamiento individualizado, que pueden involucrar a varios especialistas, son cruciales para prevenir complicaciones y mejorar la calidad de vida del paciente y su familia. Se presenta un caso clínico que ilustra la relación entre la disfagia orofaríngea y sus complicaciones en un paciente con malformaciones anatómicas craneocervicales y pulmonares. Caso clínico. Niña de 3 años con antecedentes médicos complejos incluyendo malformación congénita ósea cervical que presenta, a raíz de última intervención quirúrgica a ese nivel, episodios recurrentes de neumonía. Dados los antecedentes, se piensa como primera posibilidad diagnóstica etiología aspirativa, constatándose en el estudio disfagia a líquidos, compensable con adaptación de la dieta. A pesar del adecuado tratamiento de la disfagia, la persistencia de los episodios siempre en la misma localización hace replantearse la etiología. La TAC torácica reveló a ese nivel una malformación pulmonar, sometiéndose de forma exitosa a una lobectomía toracoscópica. Actualmente no ha vuelto a presentar neumonías de repetición y gracias al tratamiento por parte de logopeda ha presentado mejoría progresiva de su disfagia. Conclusiones. La disfagia orofaríngea es un síntoma infradiagnosticado. Es imprescindible que se empiece a codificar en informes y registros. Existen herramientas de cribado que nos facilitan su diagnóstico en cualquier nivel asistencial que deberían ser usadas sobre todo en población de riesgo. Requiere reevaluación periódica por ser un síntoma dinámico.(AU)

Introduction: Oropharyngeal dysphagia, or difficulty swallowing, may be due to anatomic abnormality, including cervical malformations. A comprehensive assessment and an individualized care, which may include multiple specialists, are crucial in preventing complications and improving the quality of life for both the patient and family. A clinical case is presented that illustrates the relationship between oropharyngeal dysphagia and its complications in a patient with craniocervical and pulmonary malformations. Case report. 3-year-old girl with a complex medical history including congenital cervical bone malformation, who presents with recurrent episodes of pneumonia following her last surgical intervention at that level. Given her medical history, aspirational etiology is considered as first diagnostic possibility with studies confirming dysphagia to liquids, compensable with dietary adaptation. Despite adequate treatment of dysphagia the persistence of episodes, always in the same location, makes us reconsider the etiology. The chest CT revealed a pulmonary malformation at that level and the patient underwent a successful thoracoscopic lobectomy. Currently, she has not had recurrent pneumonia and, thanks to treatment by a speech therapist, she has shown progressive improvement in her dysphagia. Conclusions. Oropharyngeal dysphagia is an underdiagnosed symptom. It is essential we begin to codify it in reports and records. There are screening tools to facilitate the diagnosis at any level of health care that should be used especially in at risk population. It requires periodic reevaluation as it is a dynamic symptom.(AU)

Hipocondroplasia en pediatría: reporte de un caso / Hypocondroplasya in pediatrics: case study / Hipocondroplasia em pediatia: relato de caso

La hipocondroplasia es una displasia esquelética caracterizada por baja estatura, constitución robusta, brazos y piernas desproporcionadamente cortos, manos y pies anchos y cortos, leve laxitud articular y macrocefalia. Los niños generalmente se presentan como pequeños, con velocidad de crecimiento disminuida, que conduce a una baja estatura y desproporción de las extremidades. La hipocondroplasia en la mayoría de los casos se hereda con carácter autosómico dominante, aunque se detectan numerosos casos esporádicos. El diagnóstico requiere una exhaustiva anamnesis y adecuada exploración física. Es importante valorar algunos indicadores de crecimiento como: peso para la edad, longitud/talla para la edad, relación entre peso y longitud/talla, velocidad de crecimiento, talla diana genética, medidas de segmentos corporales, entre otros. Las radiografías esqueléticas permiten diagnosticar la mayoría de las displasias óseas. Los estudios moleculares suelen ser la prueba de confirmación y se solicitan ante una sospecha diagnóstica. Es importante incluir las displasias óseas en el diagnóstico diferencial de la talla baja y tenerlas en cuenta ante cualquier caso de talla baja disarmónica con alteraciones fenotípicas. La hipocondroplasia en la actualidad, no es una indicación aprobada para tratamiento con hormona del crecimiento. Se presenta un caso clínico de una niña de 14 meses, con talla baja severa, desproporcionada, que presentó dificultades para llegar al diagnóstico definitivo de hipocondroplasia.

Hypochondroplasia is a skeletal dysplasia characterized by short height, robust build, disproportionately short arms and legs, short and broad hands and feet, mild joint laxity, and macrocephaly. Children generally show slow growth rate, which leads to short stature and limb disproportion. Hypochondroplasia is mostly inherited with an autosomal dominant character, although many sporadic cases have been detected. Diagnosis requires a thorough history and adequate physical examination. It is important to assess some growth indicators such as: weight for age, length/height for age, relationship between weight and length/height, growth speed, genetic target height, measurements of body segments, among others. Skeletal XRs can diagnose most bone dysplasias. Molecular studies are usually the confirmatory test and are requested when a diagnosis is suspected. It is important to include bone dysplasias in the differential diagnosis of short stature and to take them into account for any disharmonious short stature with phenotypic alterations. Hypochondroplasia is currently not an approved indication for growth hormone therapy. We present a clinical case of a 14-month-old girl, with a severe, disproportionate short stature, who presented difficulties in her definitive hypochondroplasia diagnosis.

A hipocondroplasia é uma displasia esquelética caracterizada por baixa estatura, constituição robusta, braços e pernas desproporcionalmente curtos, mãos e pés largos e curtos, frouxidão articular leve e macrocefalia. As crianças geralmente são pequenas, com diminuição da velocidade de crescimento, o que leva à baixa estatura e desproporção dos membros. A hipocondroplasia na maioria dos casos é herdada com caráter autossômico dominante, embora sejam detectados numerosos casos esporádicos. O diagnóstico requer uma história completa e um exame físico adequado. É importante avaliar alguns indicadores de crescimento como: peso para idade, comprimento/altura para idade, relação entre peso e comprimento/altura, taxa de crescimento, estatura alvo genético, medidas de segmentos corporais, entre outros. As radiografias esqueléticas permitem o diagnóstico da maioria das displasias ósseas. Os estudos moleculares são geralmente o teste de confirmação e são solicitados quando há suspeita de diagnóstico. É importante incluir as displasias ósseas no diagnóstico diferencial da baixa estatura e considerá-las em qualquer caso de baixa estatura desarmônica com alterações fenotípicas. A hipocondroplasia não é atualmente uma indicação aprovada para o tratamento com hormônio de crescimento. Apresenta-se o caso clínico de uma menina de 14 meses, com baixa estatura grave e desproporcional, que apresentou dificuldades em chegar ao diagnóstico definitivo de hipocondroplasia.

Alargamiento óseo con clavos magnéticos. Experiencia en pacientes menores de 18 años / Bone lengthening with magnetic nails. Experience in patients younger than 18

Antecedentes y objetivo: El alargamiento óseo con clavos endomedulares magnéticos (CEM) se plantea como alternativa ventajosa a otros alargamientos, al eliminar los inconvenientes de la fijación externa. El objetivo de este trabajo es analizar los resultados y valorar las complicaciones en una serie de pacientes menores de 18 años. Material y métodos: Entre 2014 y 2019 se han realizado 31 alargamientos con CEM tipo Precice2® (23 fémures, 8 tibias), en 28 pacientes menores de 18 años (15 varones y 13 mujeres). Este estudio retrospectivo observacional incluye pacientes con seguimiento de más de 18 meses. La edad media ha sido de 14,4 años (8-18). Los aspectos más relevantes analizados han sido: acortamiento/deformidad previos, alargamiento/corrección conseguidos y tiempo hasta carga completa. Además, se han revisado las complicaciones y reintervenciones. Resultados: El alargamiento conseguido ha sido de 5,5cm de media (3-8). En 28 alargamientos (90,3%) se ha conseguido o superado el objetivo planificado. El índice de curación (IC) medio fue de 1,1 meses/cm. Más de la mitad de los alargamientos (55%) han presentado alguna complicación. Aunque estas solo han dejado secuelas permanentes en 2 pacientes (7,1%), 9 de ellos han precisado reintervención (13 operaciones). No ha habido infecciones. Conclusiones: La elongación ósea con CEM en pacientes menores de 18 años ha conseguido su objetivo en más de un 90% de casos de manera eficaz, precisa y segura. En esta serie, los CEM han eliminado la necesidad de fijadores externos y han tutorizado eficazmente el segmento operado. La alta incidencia de complicaciones sigue siendo preocupante.(AU)

Background and goal: Bone elongation with magnetic endomedullary nails (MEN) has been proposed as an advantageous alternative to other techniques, by eliminating the drawbacks of external fixation. The aim of this work is to analyze the results and assess the complications in a series of patients under the age of 18. Material and methods: From 2014 to 2019, 31 elongations (23 femurs, 8 tibias) using MEN (Precice2™) have been performed in 28 patients younger than 18 (15 males and 13 females). In this observational retrospective study, only patients with follow-up longer than 18 months have been included. The average age has been 14.4 years (8–18). The most relevant aspects analyzed have been: previous shortening/deformity, elongation/correction achieved and time to full weight bearing. Complications and re-interventions have also been assessed. Results: The elongation achieved has been 5.5cm on average (3–8). In 28 elongations (90.3%) the planned goal of lengthening was achieved. The mean healing index was 1.1months/cm. More than half of elongations (55%) presented complications. Although they produced permanent sequelae in only two patients (7.1%), a total of 9 patients required re-intervention (13 operations). No infections were detected. Conclusions: Bone lengthening with MEN in individuals younger than 18 has achieved its goal in more than 90% of patients in an effective, accurate and safe manner. The use of MEN in this series has eliminated the need for external fixators and has successfully tutorized the operated segment. The high number of complications detected in this study remains a concern.(AU)

[Translated article] Bone lengthening with magnetic nails. Experience in patients younger than 18 / Alargamiento óseo con clavos magnéticos. Experiencia en pacientes menores de 18 años

Antecedentes y objetivo: El alargamiento óseo con clavos endomedulares magnéticos (CEM) se plantea como alternativa ventajosa a otros alargamientos, al eliminar los inconvenientes de la fijación externa. El objetivo de este trabajo es analizar los resultados y valorar las complicaciones en una serie de pacientes menores de 18 años. Material y métodos: Entre 2014 y 2019 se han realizado 31 alargamientos con CEM tipo Precice2® (23 fémures, 8 tibias), en 28 pacientes menores de 18 años (15 varones y 13 mujeres). Este estudio retrospectivo observacional incluye pacientes con seguimiento de más de 18 meses. La edad media ha sido de 14,4 años (8-18). Los aspectos más relevantes analizados han sido: acortamiento/deformidad previos, alargamiento/corrección conseguidos y tiempo hasta carga completa. Además, se han revisado las complicaciones y reintervenciones. Resultados: El alargamiento conseguido ha sido de 5,5cm de media (3-8). En 28 alargamientos (90,3%) se ha conseguido o superado el objetivo planificado. El índice de curación (IC) medio fue de 1,1 meses/cm. Más de la mitad de los alargamientos (55%) han presentado alguna complicación. Aunque estas solo han dejado secuelas permanentes en 2 pacientes (7,1%), 9 de ellos han precisado reintervención (13 operaciones). No ha habido infecciones. Conclusiones: La elongación ósea con CEM en pacientes menores de 18 años ha conseguido su objetivo en más de un 90% de casos de manera eficaz, precisa y segura. En esta serie, los CEM han eliminado la necesidad de fijadores externos y han tutorizado eficazmente el segmento operado. La alta incidencia de complicaciones sigue siendo preocupante.(AU)

Background and goal: Bone elongation with magnetic endomedullary nails (MEN) has been proposed as an advantageous alternative to other techniques, by eliminating the drawbacks of external fixation. The aim of this work is to analyze the results and assess the complications in a series of patients under the age of 18. Material and methods: From 2014 to 2019, 31 elongations (23 femurs, 8 tibias) using MEN (Precice2™) have been performed in 28 patients younger than 18 (15 males and 13 females). In this observational retrospective study, only patients with follow-up longer than 18 months have been included. The average age has been 14.4 years (8–18). The most relevant aspects analyzed have been: previous shortening/deformity, elongation/correction achieved and time to full weight bearing. Complications and re-interventions have also been assessed. Results: The elongation achieved has been 5.5cm on average (3–8). In 28 elongations (90.3%) the planned goal of lengthening was achieved. The mean healing index was 1.1months/cm. More than half of elongations (55%) presented complications. Although they produced permanent sequelae in only two patients (7.1%), a total of 9 patients required re-intervention (13 operations). No infections were detected. Conclusions: Bone lengthening with MEN in individuals younger than 18 has achieved its goal in more than 90% of patients in an effective, accurate and safe manner. The use of MEN in this series has eliminated the need for external fixators and has successfully tutorized the operated segment. The high number of complications detected in this study remains a concern.(AU)

WDR35 variants in a cranioectodermal dysplasia patient with early onset end-stage renal disease and retinal dystrophy.

Cranioectodermal dysplasia (CED) is rare heterogeneous condition. It belongs to a group of disorders defined as ciliopathies and is associated with defective cilia function and structure. To date six genes have been associated with CED. Here we describe a 4-year-old male CED patient whose features include dolichocephaly, multi-suture craniosynostosis, epicanthus, frontal bossing, narrow thorax, limb shortening, and brachydactyly. The patient presented early-onset chronic kidney disease and was transplanted at the age of 2 years and 5 months. At the age of 3.5 years a retinal degeneration was diagnosed. Targeted sequencing by NGS revealed the presence of compound heterozygous variants in the WDR35 gene. The variants are a novel missense change in exon 9 p.(Gly303Arg) and a previously described nonsense variant in exon 18 p.(Leu641*). Our findings suggest that patients with WDR35 defects may be at risk to develop early-onset retinal degeneration. Therefore, CED patients with pathogenic variation in this gene should be assessed at least once by the ophthalmologist before the age of 4 years to detect early signs of retinal degeneration.

Clinical and radiologic evaluation of a Turkish family with hypochondroplasia and a rare FGFR3 variant.

OBJECTIVES: Hypochondroplasia (HCH) is characterized by disproportionate short stature and regarded as a milder form of achondroplasia (ACH), which is another skeletal dysplasia, both caused by variants in fibroblast growth factor receptor 3 (FGFR3) gene. HCH diagnosis is based on the clinical features and skeletal survey findings. The most common FGFR3 variant in HCH affects the codon 540, leading to substitution of asparagine with lysine in about 70% of patients. CASE PRESENTATION: Herein, we described the clinical and radiographical manifestations of HCH in affected members of a Turkish family with very rare Asn540Thr (c.1619A>C) variant within hot spot of the gene for this condition. CONCLUSIONS: This is a very rarely reported variant in the literature and this report is the first case with this variant in Turkish population. The report also presents the phenotypic variability within a family with the same variant, which is inherent to HCH.

Bone pain management with opioid medication in a patient with Camurati-Engelmann disease: a case report / Manejo del dolor óseo con medicación opioide en una paciente con enfermedad de Camurati-Engelmann: reporte de un caso

Introduction: Camurati-Engelman Disease is a rare genetic sclerosing bone dysplasia with periosteal and endosteal thickening of the cortical of the long bones. It generates pain secondary to the reduction of the medullary canal that is usually controlled with corticosteroids and, in severe cases, with surgical decompression. Case history: We present the case of a woman with a genetic diagnosis of Camurati-Engelman Disease with poor pain control with corticosteroid management and surgical procedures throughout her childhood and early adulthood. In whom optimal pain control was achieved with pain regimen with hydrocodone analgesic management. This is the first case described in the literature for adequate pain control using an opioid drug. Discussion: CE disease is an extremely rare genetic entity with little more than 300 cases reported in the world. It is generated by an alteration in the gene for growth factor-beta 1 (TGF-B1); it has a varied clinical presentation that can begin with bone alterations accompanied by muscle weakness, joint angular alterations, headache, and nerve compressions. It has a differential diagnosis with some genetic entities that may present clinical similarity, but its morphological and radiological characteristics are distinctive. The usual management of bone pain generated by this entity is based on corticosteroids, in addition to losartan or surgical intervention aimed at reducing cortical changes. The intervention with opioid analgesics accompanied by a rehabilitation plan is not a frequent report, this being a case of success due to the refractoriness of the symptoms in a patient with chronic pain, with a positive impact on her functionality and quality of life. Conclusion: It is considered that analgesic management with opioids may be a treatment option in patients with Camurati-Engelman disease refractory to corticosteroid management and surgical interventions.(AU)

Introducción: La enfermedad de Camurati-Engelman (CE) es una displasia ósea esclerosante rara, de causa genética. Se presenta con engrosamiento perióstico y endóstico de la cortical de los huesos largos. Genera dolor secundario a la reducción del canal medular, que habitualmente se controla con corticoides y en casos severos, con descompresión quirúrgica. Historia del caso: Presentamos el caso de una mujer con diagnóstico genético de enfermedad de Camurati-Engelman, con mal control del dolor, con manejo de corticosteroides y procedimientos quirúrgicos a lo largo de su niñez y adultez temprana. Se logró un control óptimo del dolor con un régimen con manejo analgésico con hidrocodona. Este es el primer caso descrito en la literatura de un adecuado control del dolor con un medicamento opioide. Discusión: La enfermedad de CE es una entidad genética extremadamente rara, con poco más de 300 casos reportados en el mundo. Se genera por una alteración en el gen del factor de crecimiento beta 1 (TGF-B1). Tiene una presentación clínica variada que puede iniciar con las alteraciones óseas acompañado de debilidad muscular, alteraciones angulares articulares, cefalea y compresiones nerviosas. Tiene diagnóstico diferencial con algunas entidades genéticas que pueden presentar similitud clínica, pero su característica morfológica y radiológica es distintiva. El manejo usual del dolor óseo generado por esta entidad se basa en corticoesteroides, además de losartán o intervenciones quirúrgicas orientadas a disminuir los cambios corticales. La intervención con analgésicos opioides, acompañada de un plan de rehabilitación, no es un reporte frecuente, siendo este un caso de éxito ante la refractariedad de los síntomas en una paciente con dolor crónico, impactando de manera positiva en su funcionalidad y calidad de vida.(AU)

Hypochondroplasia and temporal lobe epilepsy - A series of 4 cases.

Hypochondroplasia is a skeletal dysplasia syndrome with an autosomal dominant inheritance. It may be associated with temporal lobe epilepsy. We present a series of four patients (two female, two male) with hypochondroplasia who presented at our center with drug refractory epilepsy. Clinical details and EEG and MRI findings led to a diagnosis of temporal lobe epilepsy in all four cases. The MRI findings indicate the epilepsy in hypochondroplasia may be associated with bilateral temporal lobe dysgenesis.

Molecular genetic analysis and growth hormone response in patients with syndromic short stature.

BACKGROUND: Syndromic short stature is a genetic and phenotypic heterogeneous disorder with multiple causes. This study aims to identify genetic causes in patients with syndromic short stature of unknown cause and evaluate the efficacy of the growth hormone response. METHODS: Trio-whole-exome sequencing was applied to identify pathogenic gene mutations in seven patents with short stature, multiple malformations, and/or intellectual disability. Whole-genome low-coverage sequencing was also performed to identify copy number variants in three patients with concurrent intellectual disability. Recombinant human growth hormone was administered to improve height in patients with an identified cause of syndromic short stature. RESULTS: Of the seven patients, three pathogenic/likely pathogenic gene mutations, including one FGFR3 mutation (c.1620C>A p.N540K), one novel GNAS mutation (c.2288C>T p.A763V), and one novel TRPS1 mutation (c.2527_c.2528dupTA p.S843fsX72), were identified in three patients. No copy number variants were identified in the three patients with concurrent intellectual disability. The proband with an FGFR3 mutation, a female 4 and 3/12 years of age, was diagnosed with hypochondroplasia. Long-acting growth hormone improved her height from 85.8 cm [- 5.05 standard deviation (SD)] to 100.4 cm (- 4.02 SD), and her increased height SD score (SDS) was 1.03 after 25 months of treatment. The proband with a GNAS mutation, a female 12 and 9/12 years of age, was diagnosed with pseudohypoparathyroidism Ia. After 14 months of treatment with short-acting growth hormone, her height improved from 139.3 cm (- 2.69 SD) to 145.0 cm (- 2.36 SD), and her increased height SDS was 0.33. CONCLUSIONS: Trio-whole-exome sequencing was an important approach to confirm genetic disorders in patients with syndromic short stature of unknown etiology. Short-term growth hormone was effective in improving height in patients with hypochondroplasia and pseudohypoparathyroidism Ia.

High-Resolution Melting Analysis for Rapid Detection of Mutations in Patients with FGFR3-Related Skeletal Dysplasias.

Background: Mutations in the fibroblast growth factor receptor 3 (FGFR3) gene are related to skeletal dysplasias (SDs): acondroplasia (ACH), hypochodroplasia (HCH) and type I (TDI) and II (TDII) tanatophoric dysplasias. This study was designed to standardize and implement a high-resolution melting (HRM) technique to identify mutations in patients with these phenotypes. Methods: Initially, FGFR3 gene segments from 84 patients were PCR amplified and subjected to Sanger sequencing. Samples from 29 patients positive for mutations were analyzed by HRM. Results: Twelve of the patients FGFR3 mutations had ACH (six g.16081 G > A, three g.16081 G > C and three g.16081 G > A + g.16002 C > T); thirteen of patients with HCH had FGFR3 mutations (eight g.17333 C > A, five g.17333 C > G and five were negative); and four patients with DTI had FGFR3 mutations (three g.13526 C > T and one g.16051G > T and two patients with DTII (presented mutation g.17852 A > G). When analyzing the four SDs altogether, an overlap of the dissociation curves was observed, making genotyping difficult. When analyzed separately, however, the HRM analysis method proved to be efficient for discriminating among the mutations for each SD type, except for those patients carrying additional polymorphism concomitant to the recurrent mutation. Conclusion: We conclude that for recurrent mutations in the FGFR3 gene, that the HRM technique can be used as a faster, reliable and less expensive genotyping routine for the diagnosis of these pathologies than Sanger sequencing.

High prevalence of variants in skeletal dysplasia associated genes in individuals with short stature and minor skeletal anomalies.

OBJECTIVE: Next generation sequencing (NGS) has expanded the diagnostic paradigm turning the focus to the growth plate. The aim of the study was to determine the prevalence of variants in genes implicated in skeletal dysplasias in probands with short stature and mild skeletal anomalies. DESIGN: Clinical and radiological data were collected from 108 probands with short stature and mild skeletal anomalies. METHODS: A customized skeletal dysplasia NGS panel was performed. Variants were classified using ACMG recommendations and Sherloc. Anthropometric measurements and skeletal anomalies were subsequently compared in those with or without an identified genetic defect. RESULTS: Heterozygous variants were identified in 21/108 probands (19.4%). Variants were most frequently identified in ACAN (n = 10) and IHH (n = 7) whilst one variant was detected in COL2A1, CREBBP, EXT1, and PTPN11. Statistically significant differences (P < 0.05) were observed for sitting height/height (SH/H) ratio, SH/H ratio standard deviation score (SDS), and the SH/H ratio SDS >1 in those with an identified variant compared to those without. CONCLUSIONS: A molecular defect was elucidated in a fifth of patients. Thus, the prevalence of mild forms of skeletal dysplasias is relatively high in individuals with short stature and mild skeletal anomalies, with variants in ACAN and IHH accounting for 81% of the cases. An elevated SH/H ratio appears to be associated with a greater probability in detecting a variant, but no other clinical or radiological feature has been found determinant to finding a genetic cause. Currently, we cannot perform extensive molecular studies in all short stature individuals so detailed clinical and radiological phenotyping may orientate which are the candidate patients to obtain worthwhile results. In addition, detailed phenotyping of probands and family members will often aid variant classification.

Ttc30a affects tubulin modifications in a model for ciliary chondrodysplasia with polycystic kidney disease.

Skeletal ciliopathies (e.g., Jeune syndrome, short rib polydactyly syndrome, and Sensenbrenner syndrome) are frequently associated with nephronophthisis-like cystic kidney disease and other organ manifestations. Despite recent progress in genetic mapping of causative loci, a common molecular mechanism of cartilage defects and cystic kidneys has remained elusive. Targeting two ciliary chondrodysplasia loci (ift80 and ift172) by CRISPR/Cas9 mutagenesis, we established models for skeletal ciliopathies in Xenopus tropicalis Froglets exhibited severe limb deformities, polydactyly, and cystic kidneys, closely matching the phenotype of affected patients. A data mining-based in silico screen found ttc30a to be related to known skeletal ciliopathy genes. CRISPR/Cas9 targeting replicated limb malformations and renal cysts identical to the models of established disease genes. Loss of Ttc30a impaired embryonic renal excretion and ciliogenesis because of altered posttranslational tubulin acetylation, glycylation, and defective axoneme compartmentalization. Ttc30a/b transcripts are enriched in chondrocytes and osteocytes of single-cell RNA-sequenced embryonic mouse limbs. We identify TTC30A/B as an essential node in the network of ciliary chondrodysplasia and nephronophthisis-like disease proteins and suggest that tubulin modifications and cilia segmentation contribute to skeletal and renal ciliopathy manifestations of ciliopathies in a cell type-specific manner. These findings have implications for potential therapeutic strategies.

Skeletal Deformities in Osterix-Cre;Tgfbr2f/f Mice May Cause Postnatal Death.

Transforming growth factor ß (TGFß) signaling plays an important role in skeletal development. We previously demonstrated that the loss of TGFß receptor II (Tgfbr2) in Osterix-Cre-expressing mesenchyme results in defects in bones and teeth due to reduced proliferation and differentiation in pre-osteoblasts and pre-odontoblasts. These Osterix-Cre;Tgfbr2f/f mice typically die within approximately four weeks for unknown reasons. To investigate the cause of death, we performed extensive pathological analysis on Osterix-Cre- (Cre-), Osterix-Cre+;Tgfbr2f/wt (HET), and Osterix-Cre+;Tgfbr2f/f (CKO) mice. We also crossed Osterix-Cre mice with the ROSA26mTmG reporter line to identify potential off-target Cre expression. The findings recapitulated published skeletal and tooth abnormalities and revealed previously unreported osteochondral dysplasia throughout both the appendicular and axial skeletons in the CKO mice, including the calvaria. Alterations to the nasal area and teeth suggest a potentially reduced capacity to sense and process food, while off-target Cre expression in the gastrointestinal tract may indicate an inability to absorb nutrients. Additionally, altered nasal passages and unexplained changes in diaphragmatic muscle support the possibility of hypoxia. We conclude that these mice likely died due to a combination of breathing difficulties, malnutrition, and starvation resulting primarily from skeletal deformities that decreased their ability to sense, gather, and process food.

Loss of Wnt16 Leads to Skeletal Deformities and Downregulation of Bone Developmental Pathway in Zebrafish.

Wingless-type MMTV integration site family, member 16 (wnt16), is a wnt ligand that participates in the regulation of vertebrate skeletal development. Studies have shown that wnt16 can regulate bone metabolism, but its molecular mechanism remains largely undefined. We obtained the wnt16-/- zebrafish model using the CRISPR-Cas9-mediated gene knockout screen with 11 bp deletion in wnt16, which led to the premature termination of amino acid translation and significantly reduced wnt16 expression, thus obtaining the wnt16-/- zebrafish model. The expression of wnt16 in bone-related parts was detected via in situ hybridization. The head, spine, and tail exhibited significant deformities, and the bone mineral density and trabecular bone decreased in wnt16-/- using light microscopy and micro-CT analysis. RNA sequencing was performed to explore the differentially expressed genes (DEGs). Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis found that the down-regulated DEGs are mainly concentrated in mTOR, FoxO, and VEGF pathways. Protein-protein interaction (PPI) network analysis was performed with the detected DEGs. Eight down-regulated DEGs including akt1, bnip4, ptena, vegfaa, twsg1b, prkab1a, prkab1b, and pla2g4f.2 were validated by qRT-PCR and the results were consistent with the RNA-seq data. Overall, our work provides key insights into the influence of wnt16 gene on skeletal development.

Short exposure to glyphosate induces locomotor, craniofacial, and bone disorders in zebrafish (Danio rerio) embryos.

Glyphosate [N-(phosphonomethyl)glycine] is the active ingredient in widely used broad-spectrum herbicides. Even though the toxicity mechanism of this herbicide in vertebrates is poorly understood, evidence suggests that glyphosate is an endocrine disruptor capable of producing morphological anomalies as well as cardiotoxic and neurotoxic effects. We used the zebrafish model to assess the effects of early life glyphosate exposure on the development of cartilage and bone tissues and organismal responses. We found functional alterations, including a reduction in the cardiac rate, significant changes in the spontaneous tail movement pattern, and defects in craniofacial development. These effects were concomitant with alterations in the level of the estrogen receptor alpha osteopontin and bone sialoprotein. We also found that embryos exposed to glyphosate presented spine deformities as adults. These developmental alterations are likely induced by changes in protein levels related to bone and cartilage formation.

Developmental phenotypic and transcriptomic effects of exposure to nanomolar levels of metformin in zebrafish.

Metformin is found in the majority of lakes and streams in the United States, leading to widespread environmental exposure. Results of the present study indicate that extended duration metformin exposure at critical developmental periods leads to decreased survival rates in zebrafish (danio rerio), an NIH approved human model. Significant abnormalities are seen with extended duration metformin exposure from 4 h post fertilization up to 5 days post fertilization, although short term metformin exposure for 24 h at 4-5 days post fertilization did not lead to any significant abnormalities. Both extended and short term duration did however have an impact on locomotor activity of zebrafish, and several genes involved in neurological and cardiovascular development were differentially expressed after exposure to metformin. The changes seen in behavior, gene expression and morphological abnormalities caused by metformin exposure should be examined further in future studies in order to assess their potential human health implications as metformin prescriptions continue to increase worldwide.