Genotype-phenotype correlation at codon 1740 ofSETD2

The SET domain containing 2, histone lysine methyltransferase encoded by SETD2 is a dual-function methyltransferase for histones and microtubules and plays an important role for transcriptional regulation, genomic stability, and cytoskeletal functions. Specifically, SETD2 is associated with trimethylation of histone H3 at lysine 36 (H3K36me3) and methylation of α-tubulin at lysine 40. Heterozygous loss of function and missense variants have previously been described with Luscan-Lumish syndrome (LLS), which is characterized by overgrowth, neurodevelopmental features, and absence of overt congenital anomalies. We have identified 15 individuals with de novo variants in codon 1740 of SETD2 whose features differ from those with LLS. Group 1 consists of 12 individuals with heterozygous variant c.5218C>T p.(Arg1740Trp) and Group 2 consists of 3 individuals with heterozygous variant c.5219G>A p.(Arg1740Gln). The phenotype of Group 1 includes microcephaly, profound intellectual disability, congenital anomalies affecting several organ systems, and similar facial features. Individuals in Group 2 had moderate to severe intellectual disability, low normal head circumference, and absence of additional major congenital anomalies. While LLS is likely due to loss of function of SETD2, the clinical features seen in individuals with variants affecting codon 1740 are more severe suggesting an alternative mechanism, such as gain of function, effects on epigenetic regulation, or posttranslational modification of the cytoskeleton. Our report is a prime example of different mutations in the same gene causing diverging phenotypes and the features observed in Group 1 suggest a new clinically recognizable syndrome uniquely associated with the heterozygous variant c.5218C>T p.(Arg1740Trp) in SETD2

Unusual mechanical failures of intrathecal baclofen pump systems: symptoms, signs, and trouble shooting

Introduction!#!Although intrathecal baclofen (ITB) therapy is an effective treatment for spasticity, it has several disadvantages and a risk of complications.!##!Methods!#!We present six pediatric patients who suffered from unusual mechanical failures of intrathecal baclofen pump systems.!##!Results!#!With these case-vignettes, we provide a systematic approach on how to interpret the symptoms of ITB complications and an advice which further diagnostic and therapeutic steps to follow. We underline the seriousness of baclofen overdose, underdosing or withdrawal

A Case Report: First Long-Term Treatment With Burosumab in a Patient With Cutaneous-Skeletal Hypophosphatemia Syndrome

Epidermal nevus syndromes encompass a highly heterogeneous group of systemic disorders, characterized by epidermal nevi, and a spectrum of neuromuscular, ocular, and bone abnormalities. Cutaneous-skeletal hypophosphatemia syndrome (CSHS) constitutes a specific sub-entity in which elevated levels of fibroblast growth factor-23 cause hypophosphatemic rickets that are, to date, not amenable to causal therapy. Here, we report the first long-term follow-up of causal treatment with burosumab in a 3-year-old female patient with CSHS. 4 weeks after initiation of burosumab treatment, serum phosphate normalized to age-appropriate levels. Furthermore, long-term follow-up of 42 months revealed significant improvement of linear growth and gross physical functions, including respiratory insufficiency. Radiographic rickets severity as well as subjective bone pain were strongly reduced, and no side effects were observed over the course of treatment. In summary, we, here, report about a successful treatment of hypophosphatemic rickets in CSHS with burosumab over the time course of 42 months. In our patient, burosumab showed convincing efficacy and safety profile, without any loss of effect or increase of dose

Tracheal Tube Misplacement after Emergency Intubation in Pediatric Trauma Patients: A Retrospective, Exploratory Study

Inadvertent tracheal tube misplacement and particularly endobronchial intubation are well-known complications of emergency endotracheal intubation (ETI) in pediatric trauma patients, which require repositioning of the tube to avoid impairment of gas exchange. The main aim of study was to identify the frequency of tube misplacement and associated factors of pediatric trauma patients who received ETI either by prehospital physician-staffed emergency medical service (EMS), or at emergency department (ED) admission to a single level-1 trauma center. Sixty-five patients (median age 14 years and median injury severity score 29) were included. Of these, 30 underwent helicopter EMS ETI, 29 ground EMS ETI, and 6 ED ETI. Seventeen cases (26%) of tracheal tube misplacement were recognized. After multivariable analysis, tracheal tube misplacement was independently negatively associated with body weight (OR 0.86; 95% CI, 0.76–0.99; p = 0.032) and helicopter EMS ETI (OR 0.20; 95% CI, 0.04–0.97; p = 0.036). Two of nineteen patients received tube thoracostomy due to endobronchial intubation. Mortality and length of stay were comparable in patients with misplaced tubes and correctly placed tubes. The results suggest that particularly small children require attention to avoid tracheal tube misplacement, which emphasizes the need for special training. Helicopter EMS physicians’ expertise might be beneficial in prehospital pediatric trauma patients requiring advanced airway management

Genotype–phenotype correlation at codon 1740 of SETD2

The SET domain containing 2, histone lysine methyltransferase encoded by SETD2 is a dual-function methyltransferase for histones and microtubules and plays an important role for transcriptional regulation, genomic stability, and cytoskeletal functions. Specifically, SETD2 is associated with trimethylation of histone H3 at lysine 36 (H3K36me3) and methylation of α-tubulin at lysine 40. Heterozygous loss of function and missense variants have previously been described with Luscan-Lumish syndrome (LLS), which is characterized by overgrowth, neurodevelopmental features, and absence of overt congenital anomalies. We have identified 15 individuals with de novo variants in codon 1740 of SETD2 whose features differ from those with LLS. Group 1 consists of 12 individuals with heterozygous variant c.5218C>T p.(Arg1740Trp) and Group 2 consists of 3 individuals with heterozygous variant c.5219G>A p.(Arg1740Gln). The phenotype of Group 1 includes microcephaly, profound intellectual disability, congenital anomalies affecting several organ systems, and similar facial features. Individuals in Group 2 had moderate to severe intellectual disability, low normal head circumference, and absence of additional major congenital anomalies. While LLS is likely due to loss of function of SETD2, the clinical features seen in individuals with variants affecting codon 1740 are more severe suggesting an alternative mechanism, such as gain of function, effects on epigenetic regulation, or posttranslational modification of the cytoskeleton. Our report is a prime example of different mutations in the same gene causing diverging phenotypes and the features observed in Group 1 suggest a new clinically recognizable syndrome uniquely associated with the heterozygous variant c.5218C>T p.(Arg1740Trp) in SETD2

Biallelic MADD variants cause a phenotypic spectrum ranging from developmental delay to a multisystem disorder

In pleiotropic diseases, multiple organ systems are affected causing a variety of clinical manifestations. Here, we report a pleiotropic disorder with a unique constellation of neurological, endocrine, exocrine, and haematological findings that is caused by biallelic MADD variants. MADD, the mitogen-activated protein kinase (MAPK) activating death domain protein, regulates various cellular functions, such as vesicle trafficking, activity of the Rab3 and Rab27 small GTPases, tumour necrosis factor-α (TNF-α)-induced signalling and prevention of cell death. Through national collaboration and GeneMatcher, we collected 23 patients with 21 different pathogenic MADD variants identified by next-generation sequencing. We clinically evaluated the series of patients and categorized the phenotypes in two groups. Group 1 consists of 14 patients with severe developmental delay, endo- and exocrine dysfunction, impairment of the sensory and autonomic nervous system, and haematological anomalies. The clinical course during the first years of life can be potentially fatal. The nine patients in Group 2 have a predominant neurological phenotype comprising mild-to-severe developmental delay, hypotonia, speech impairment, and seizures. Analysis of mRNA revealed multiple aberrant MADD transcripts in two patient-derived fibroblast cell lines. Relative quantification of MADD mRNA and protein in fibroblasts of five affected individuals showed a drastic reduction or loss of MADD. We conducted functional tests to determine the impact of the variants on different pathways. Treatment of patient-derived fibroblasts with TNF-α resulted in reduced phosphorylation of the extracellular signal-regulated kinases 1 and 2, enhanced activation of the pro-apoptotic enzymes caspase-3 and -7 and increased apoptosis compared to control cells. We analysed internalization of epidermal growth factor in patient cells and identified a defect in endocytosis of epidermal growth factor. We conclude that MADD deficiency underlies multiple cellular defects that can be attributed to alterations of TNF-α-dependent signalling pathways and defects in vesicular trafficking. Our data highlight the multifaceted role of MADD as a signalling molecule in different organs and reveal its physiological role in regulating the function of the sensory and autonomic nervous system and endo- and exocrine glands.status: publishe

Biallelic MADD variants cause a phenotypic spectrum ranging from developmental delay to a multisystem disorder

In pleiotropic diseases, multiple organ systems are affected causing a variety of clinical manifestations. Here, we report a pleiotropic disorder with a unique constellation of neurological, endocrine, exocrine, and haematological findings that is caused by biallelic MADD variants. MADD, the mitogen-activated protein kinase (MAPK) activating death domain protein, regulates various cellular functions, such as vesicle trafficking, activity of the Rab3 and Rab27 small GTPases, tumour necrosis factor-α (TNF-α)-induced signalling and prevention of cell death. Through national collaboration and GeneMatcher, we collected 23 patients with 21 different pathogenic MADD variants identified by next-generation sequencing. We clinically evaluated the series of patients and categorized the phenotypes in two groups. Group 1 consists of 14 patients with severe developmental delay, endo- and exocrine dysfunction, impairment of the sensory and autonomic nervous system, and haematological anomalies. The clinical course during the first years of life can be potentially fatal. The nine patients in Group 2 have a predominant neurological phenotype comprising mild-to-severe developmental delay, hypotonia, speech impairment, and seizures. Analysis of mRNA revealed multiple aberrant MADD transcripts in two patient-derived fibroblast cell lines. Relative quantification of MADD mRNA and protein in fibroblasts of five affected individuals showed a drastic reduction or loss of MADD. We conducted functional tests to determine the impact of the variants on different pathways. Treatment of patient-derived fibroblasts with TNF-α resulted in reduced phosphorylation of the extracellular signal-regulated kinases 1 and 2, enhanced activation of the pro-apoptotic enzymes caspase-3 and -7 and increased apoptosis compared to control cells. We analysed internalization of epidermal growth factor in patient cells and identified a defect in endocytosis of epidermal growth factor. We conclude that MADD deficiency underlies multiple cellular defects that can be attributed to alterations of TNF-α-dependent signalling pathways and defects in vesicular trafficking. Our data highlight the multifaceted role of MADD as a signalling molecule in different organs and reveal its physiological role in regulating the function of the sensory and autonomic nervous system and endo- and exocrine glands