De novo PHF5A variants are associated with craniofacial abnormalities, developmental delay, and hypospadias.

PURPOSE: The SF3B splicing complex is composed of SF3B1-6 and PHF5A. We report a developmental disorder caused by de novo variants in PHF5A. METHODS: Clinical, genomic, and functional studies using subject-derived fibroblasts and a heterologous cellular system were performed. RESULTS: We studied 9 subjects with congenital malformations, including preauricular tags and hypospadias, growth abnormalities, and developmental delay who had de novo heterozygous PHF5A variants, including 4 loss-of-function (LOF), 3 missense, 1 splice, and 1 start-loss variant. In subject-derived fibroblasts with PHF5A LOF variants, wild-type and variant PHF5A mRNAs had a 1:1 ratio, and PHF5A mRNA levels were normal. Transcriptome sequencing revealed alternative promoter use and downregulated genes involved in cell-cycle regulation. Subject and control fibroblasts had similar amounts of PHF5A with the predicted wild-type molecular weight and of SF3B1-3 and SF3B6. SF3B complex formation was unaffected in 2 subject cell lines. CONCLUSION: Our data suggest the existence of feedback mechanisms in fibroblasts with PHF5A LOF variants to maintain normal levels of SF3B components. These compensatory mechanisms in subject fibroblasts with PHF5A or SF3B4 LOF variants suggest disturbed autoregulation of mutated splicing factor genes in specific cell types, that is, neural crest cells, during embryonic development rather than haploinsufficiency as pathomechanism.

Evaluation of management and guideline adherence in children with mild traumatic brain injury.

AIM: To evaluate the management and guideline adherence in children with mild traumatic brain injury (MTBI) in emergency departments (ED) in the Netherlands. METHODS: A multicentre cohort study was conducted, including children younger than 18 years with MTBI who presented within 24 hours after trauma in the ED of hospitals in the southwest region of the Netherlands, in 2014. Primary outcome measures for management were percentages of performed computed tomography (CT) scans and hospital admissions. Guideline adherence was defined as percentages of correctly following the guideline. Secondary outcome measures were differences in management and guideline adherence between hospitals. RESULTS: About 563 patients were analysed. Hospital admission was the most frequently performed management type (49.2% hospital admission vs. 30.9% CT). In only 49.7% of patients, the guideline was followed correctly. A substantial overuse of hospital admission (35%) and underuse of CT (40.1%) were found. Percentages of hospital admission and CT varied between 39.4-55.6% and 23.3-44.1%, respectively, across hospitals. Percentages of correctly following the guideline varied between 39.2-64.9% across hospitals. CONCLUSION: These findings suggest that physicians in the participating hospitals prefer hospital admission of children with MTBI instead of CT despite the current recommendations of the national MTBI guideline in the Netherlands.

Correlation between clinical and histologic findings in the human neonatal hippocampus after perinatal asphyxia.

Hypoxic ischemic encephalopathy after perinatal asphyxia is a major cause of mortality and morbidity in infants. Here, we evaluated pathologic changes in the hippocampi of a cohort of 16 deceased full-term asphyxiated infants who died from January 2000 to January 2009. Histochemical and immunocytochemical results for glial and neuronal cells were compared between cases with or without seizures and to adult and sudden infant death syndrome cases (n = 3 each). All asphyxiated infants displayed neuronal cell damage and reactive glial changes. Strong aquaporin-4 immunoreactivity was seen on astroglial cells within hippocampi in 50% of cases. In patients with seizures, the expression of metabotropic glutamate receptors was increased in glial cells. Cases with seizures displayed increased microglial activation and greater expression of the inflammatory markers interleukin 1ß and complement 1q compared with those in cases without seizures. All cases with seizures displayed alterations in the blood-brain barrier, as assessed by immunohistochemistry for albumin. These findings confirm the complex cascade of cellular and molecular changes occurring in the human neonatal hippocampus after perinatal asphyxia. These changes may contribute to seizure development leading to secondary brain damage. These data may aid in the development of therapeutic targets for neonatal seizures.

EXOSC3 mutations in pontocerebellar hypoplasia type 1: novel mutations and genotype-phenotype correlations.

BACKGROUND: Pontocerebellar hypoplasia (PCH) represents a group of neurodegenerative disorders with prenatal onset. Eight subtypes have been described thus far (PCH1-8) based on clinical and genetic features. Common characteristics include hypoplasia and atrophy of the cerebellum, variable pontine atrophy, and severe mental and motor impairments. PCH1 is distinctly characterized by the combination with degeneration of spinal motor neurons. Recently, mutations in the exosome component 3 gene (EXOSC3) have been identified in approximately half of the patients with PCH subtype 1. METHODS: We selected a cohort of 99 PCH patients (90 families) tested negative for mutations in the TSEN genes, RARS2, VRK1 and CASK. Patients in this cohort were referred with a tentative diagnose PCH type 1, 2, 4, 7 or unclassified PCH. Genetic analysis of the EXOSC3 gene was performed using Sanger sequencing. Clinical data, MR images and autopsy reports of patients positive for EXOSC3 mutations were analyzed. RESULTS: EXOSC3 mutations were found in twelve families with PCH subtype 1, and were not found in patients with other PCH subtypes. Identified mutations included a large deletion, nonsense and missense mutations. Examination of clinical data reveals a prolonged disease course in patients with a homozygous p.D132A mutation. MRI shows variable pontine hypoplasia in EXOSC3 mediated PCH, where the pons is largely preserved in patients with a homozygous p.D132A mutation, but attenuated in patients with other mutations. Additionally, bilateral cerebellar cysts were found in patients compound heterozygous for a p.D132A mutation and a nonsense allele. CONCLUSIONS: EXOSC3 mediated PCH shows clear genotype-phenotype correlations. A homozygous p.D132A mutation leads to PCH with possible survival into early puberty, and preservation of the pons. Compound heterozygosity for a p.D132A mutation and a nonsense or p.Y109N allele, a homozygous p.G31A mutation or a p.G135E mutation causes a more rapidly progressive course leading to death in infancy and attenuation of the ventral pons.Our findings imply a clear correlation between genetic mutation and clinical outcome in EXOSC3 mediated PCH, including variable involvement of the pons.

Fcγ receptor IIIA genotype is associated with rituximab response in antimyelin-associated glycoprotein neuropathy.

BACKGROUND: Treatment with anti-B cell antibody rituximab may ameliorate the disease course in a subgroup of patients with polyneuropathy associated with IgM monoclonal gammopathy. Polymorphisms of leukocyte IgG receptors (FcγR) that influence efficiency of antibody-dependent cell-mediated cytotoxicity determine rituximab efficacy in patients with lymphoma and autoimmune disease. OBJECTIVE: To investigate the association of FcγRIIA and FcγRIIIA polymorphisms with the response to rituximab treatment in a cohort of patients with polyneuropathy associated with IgM monoclonal gammopathy (PNP-IgM) with and without antimyelin-associated glycoprotein antibodies. METHODS: We determined FcγRIIA-R/H131 and FcγRIIIA-V/F158 genotypes in 27 patients with PNP-IgM using allele-specific PCR and Sanger sequencing. RESULTS: The FcγRIIIA-V/V158 genotype was associated with functional improvement (p=0.02) after 1 year. CONCLUSIONS: FcγRIIIA polymorphisms are potential biomarkers for response to rituximab treatment in polyneuropathy associated with IgM monoclonal gammopathy.

Propofol in status epilepticus: little evidence, many dangers?

INTRODUCTION: Several guidelines recommend the use of propofol for the treatment of refractory status epilepticus. An increased mortality rate in high dose, long-term treatment with propofol in adult patients was published recently. This prompted us to assess the literature on the scientific evidence for the efficacy and safety of propofol in the treatment of refractory status epilepticus. METHODS: Medline was searched and the three authors independently reviewed all Medline abstracts for selection of papers. RESULTS: We included 22 articles with original data on the use of propofol in refractory status epilepticus. Randomised clinical trials were lacking. Two non-randomised studies compared propofol with barbiturates and midazolam respectively. Both studies reported a higher risk of mortality for propofol. In addition, case reports and case series on the use of propofol as anaesthetic or sedative in children and adults reported several lethal cases. CONCLUSIONS: Serious doubts may be raised on the safety of propofol in the treatment of refractory status epilepticus. The two non-randomised studies and several case reports show an increased risk of mortality. Guidelines should not recommend the use of propofol as a routine treatment in refractory status epilepticus before a proper randomised trial has been performed.