Publications by authors named "Glenda Hendson"

Complex heart defects (CHD) are a common malformation associated with disruption of developmental pathways. The Cullin-RING ligases (CRLs) are multi-subunit E3 ubiquitin ligases in which Cullin 3 (CUL3) serves as a scaffolding subunit. Heterozygous CUL3 variants have been associated with neurodevelopmental disorders and pseudohypoaldosteronism type IIE.

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Distal arthrogryposes (DA) are a group of conditions presenting with multiple congenital contractures in the distal joints. The 10 types of DA are distinguished by different extra-articular manifestations. Heterozygous gain-of-function variants in PIEZO2 are known to cause a spectrum of DA conditions including DA type 3, DA type 5, and possibly Marden Walker syndrome, which are usually distinguished by the presence of cleft palate (DA3), ptosis and restriction in eye movements (DA5), and specific facial abnormalities and central nervous system involvement, respectively.

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Low-grade diffusely infiltrative tumour (LGDIT), SMARCB1-mutant, is a histopathological distinct low-grade lesion encountered in older children and young adults that shows epigenetic similarity with ATRT-MYC and has the potential for malignant progression.

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Monoallelic pathogenic variants in BICD2 are associated with autosomal dominant Spinal Muscular Atrophy Lower Extremity Predominant 2A and 2B (SMALED2A, SMALED2B). As part of the cellular vesicular transport, complex BICD2 facilitates the flow of constitutive secretory cargoes from the trans-Golgi network, and its dysfunction results in motor neuron loss. The reported phenotypes among patients with SMALED2A and SMALED2B range from a congenital onset disorder of respiratory insufficiency, arthrogryposis, and proximal or distal limb weakness to an adult-onset disorder of limb weakness and contractures.

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Mosaic KRAS variants and other RASopathy genes cause oculoectodermal, encephalo-cranio-cutaneous lipomatosis, and Schimmelpenning-Feuerstein-Mims syndromes, and a spectrum of vascular malformations, overgrowth and other associated anomalies, the latter of which are only recently being characterized. We describe eight individuals in total (six unreported cases and two previously reported cases) with somatic KRAS variants and variably associated features. Given the findings of somatic overgrowth (in seven individuals) and vascular or lymphatic malformations (in eight individuals), we suggest mosaic RASopathies (mosaic KRAS variants) be considered in the differential diagnosis for individuals presenting with asymmetric overgrowth and lymphatic or vascular anomalies.

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Mitochondrial complex I is encoded by 38 nuclear-encoded and 7 mitochondrial-encoded genes. is one of the 13 additional nuclear genes known as assembly factors. So far, four patients have been described with complex I deficiency caused by autosomal recessive mutations in Here, we report the fifth patient with related complex 1 deficiency presenting with prenatal onset of bilateral periventricular cysts, congenital lactic acidosis, and persistent life-limiting pulmonary hypertension.

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Mitochondrial complex I is encoded by 38 nuclear-encoded and 7 mitochondrial-encoded genes. is one of the 13 additional nuclear genes known as assembly factors. So far, four patients have been described with complex I deficiency caused by autosomal recessive mutations in Here, we report the fifth patient with related complex 1 deficiency presenting with prenatal onset of bilateral periventricular cysts, congenital lactic acidosis, and persistent life-limiting pulmonary hypertension.

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Clinical detection of sequence and structural variants in known cancer genes points to viable treatment options for a minority of children with cancer. To increase the number of children who benefit from genomic profiling, gene expression information must be considered alongside mutations. Although high expression has been used to nominate drug targets for pediatric cancers, its utility has not been evaluated in a systematic way.

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TRPV4 encodes a polymodal calcium-permeable plasma membrane channel. Dominant pathogenic mutations in TRPV4 lead to a wide spectrum of abnormal phenotypes. This is the first report of biallelic TRPV4 mutations and we describe two compound heterozygous siblings presenting with a complex phenotype including severe neuromuscular involvement.

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OBJECTIVE Focal cortical dysplasia (FCD) Type II is divided into 2 subgroups based on the absence (IIA) or presence (IIB) of balloon cells. In particular, extratemporal FCD Type IIA and IIB is not completely understood in terms of clinical, imaging, biological, and neuropathological differences. The aim of the authors was to analyze distinctions between these 2 formal entities and address clinical, MRI, and immunohistochemical features of extratemporal epilepsies in children.

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Background: Schimke immuno-osseous dysplasia (SIOD) is a multisystemic disorder caused by biallelic mutations in the SWI/SNF-related matrix-associated actin-dependent regulator of chromatin, subfamily A-like 1 (SMARCAL1) gene. Changes in gene expression underlie the arteriosclerosis and T-cell immunodeficiency of SIOD; therefore, we hypothesized that SMARCAL1 deficiency causes the focal segmental glomerulosclerosis (FSGS) of SIOD by altering renal gene expression. We tested this hypothesis by gene expression analysis of an SIOD patient kidney and verified these findings through immunofluorescent analysis in additional SIOD patients and a genetic interaction analysis in Drosophila.

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Purpose: To compare histologically transected fila from pediatric patients with tethered cord syndrome (TCS), with and without a low conus, with controls, focusing on collagenous and elastic tissue.

Methods: Thirty fila from patients with TCS, including 5 where minimal cautery was used prior to filum section, were compared with fila from 27 pediatric cadavers without TCS (controls). Sections of fila were stained with H&E, Masson trichrome and Verhoeff von Gieson elastic stains, and 7 with Gordon and Sweet's reticulin stain.

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Alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV) is a lethal lung developmental disorder caused by heterozygous point mutations or genomic deletion copy-number variants (CNVs) of FOXF1 or its upstream enhancer involving fetal lung-expressed long noncoding RNA genes LINC01081 and LINC01082. Using custom-designed array comparative genomic hybridization, Sanger sequencing, whole exome sequencing (WES), and bioinformatic analyses, we studied 22 new unrelated families (20 postnatal and two prenatal) with clinically diagnosed ACDMPV. We describe novel deletion CNVs at the FOXF1 locus in 13 unrelated ACDMPV patients.

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Congenital myopathies are a clinically and genetically heterogeneous group of muscle disorders characterized by congenital or early-onset hypotonia and muscle weakness, and specific pathological features on muscle biopsy. The phenotype ranges from foetal akinesia resulting in in utero or neonatal mortality, to milder disorders that are not life-limiting. Over the past decade, more than 20 new congenital myopathy genes have been identified.

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The advantages of autopsy have been demonstrated in pediatric oncology; however, it is unknown to what extent the utility of autopsy is in deceased children diagnosed with a pediatric brain tumor (PBT). The purpose of this study was to describe the frequency of autopsy, prevalence of clinical discrepancies, and accuracy of cancer registry death records for deceased children diagnosed with a PBT in British Columbia, Canada. A retrospective chart review was performed of medical records and autopsy reports of pediatric patients diagnosed with a PBT that died between 1982 and 2012 in British Columbia.

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Background: Schimke immuno-osseous dysplasia (SIOD) is an autosomal recessive disorder caused by mutations in SMARCAL1. A frequent complication is arteriosclerosis associated with reduced elastin expression; however, the mechanism underlying the reduced elastin expression remains unknown.

Methods: Expression of transcriptional regulators of elastin (ELN) and microRNA (miRNA) regulators of ELN messenger RNA (mRNA), ELN promoter methylation, and ELN mRNA poly(A) tail length were assessed by quantitative RT-PCR, bisulfite Sanger sequencing, and the Poly(A) Tail Length Assay Kit, respectively, in unaffected developing human aortae and in an SIOD aorta.

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Background: The cure rate for childhood intracranial ependymoma is approximately 70% in the setting of a gross total resection followed by radiation, but management remains challenging in patients with residual disease. Therefore, robust biomarkers are needed to guide the development of new targeted therapy. The authors evaluated the expression of several biomarkers in pediatric intracranial ependymoma and observed that the expression of enhancer of zeste homolog 2 (EZH2), a polycomb complex protein involved in epigenetic regulation of gene expression, was independently associated with poor survival.

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Purpose: Gross total resection (GTR) of intracranial ependymoma is an accepted goal. More controversial is radiotherapy deferral. This study reports on children treated with gross total resection who did not receive upfront adjuvant radiotherapy.

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Neonatal encephalopathy is a neurological emergency with heterogeneous etiologies and several management challenges. Neonatal encephalopathy of hypoxic-ischemic origin is associated with high rate of neonatal morbidity and mortality, and the long-term neurodevelopmental outcome of survivors with moderate to severe encephalopathy is poor. Magnetic resonance imaging now provides new insights on the diagnosis and prognosis of this condition.

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Tyrosyl-DNA phosphodiesterase 1 (Tdp1) is a DNA repair enzyme that processes blocked 3' ends of DNA breaks. Functional loss of Tdp1 causes spinocerebellar ataxia with axonal neuropathy type 1 (SCAN1). Based on the prominent cytoplasmic expression of Tdp1 in the neurons presumably affected in SCAN1, we hypothesized that Tdp1 participates in the repair of mitochondrial DNA.

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Background: Arteriosclerosis and emphysema develop in individuals with Schimke immuno-osseous dysplasia (SIOD), a multisystem disorder caused by biallelic mutations in SMARCAL1 (SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1). However, the mechanism by which the vascular and pulmonary disease arises in SIOD remains unknown.

Methods: We reviewed the records of 65 patients with SMARCAL1 mutations.

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Objective: The major form of magnetic resonance imaging-defined white matter injury (WMI) comprises diffuse lesions where the burden of small necrotic foci (microscopic necrosis) is poorly defined. We hypothesized that myelination failure associated with diffuse WMI involves an aberrant injury response linked to arrested preoligodendrocyte (preOL) maturation in reactive astrocyte-rich lesions.

Methods: A retrospective autopsy series (1983-2000) was selected for cases with diffuse WMI and analyzed relative to prospectively collected contemporary cases (2003-2010).

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NAD(P) steroid dehydrogenase-like (NSDHL) is an X-linked gene that encodes a 3β-hydroxysteroid dehydrogenase in the cholesterol biosynthetic pathway. Loss-of-function mutations in NSDHL cause Congenital Hemidysplasia with Ichthyosiform erythroderma and Limb Defects (CHILD) and CK syndromes. CHILD syndrome is a male lethal X-linked dominant disorder characterized by asymmetric skin and limb anomalies in affected females.

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We describe respiratory chain complex IV deficiency (cytochrome c oxidase deficiency) in a female infant with a neonatal rapidly progressive fatal course characterized by microcephaly, encephalopathy, persistent lactic acidosis, and hypertrophic cardiomyopathy. Postmortem cardiac muscle study showed marked complex IV deficiency. In contrast, complex IV activity was only slightly decreased in the skeletal muscle.

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