Publications by authors named "Keers S"

Background: During the early stages of the COVID-19 pandemic, concerns were raised about reduced attendance at hospitals, particularly in paediatric emergency departments, which could result in preventable poorer outcomes and late presentations among children requiring emergency care. We aimed to investigate the impact of COVID-19 on health-seeking behaviour and decision-making processes of caregivers presenting to paediatric emergency services at a National Health Service (NHS) Trust in London.

Materials And Methods: We conducted a mixed-methods study (survey and semi-structured interviews) across two hospital sites between November-December 2020.

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Background: Both pathogenic bacteria and viruses are frequently detected in the nasopharynx (NP) of children in the absence of acute respiratory infection (ARI) symptoms. The aim of this study was to estimate the aetiological fractions for ARI hospitalisation in children for respiratory syncytial virus (RSV) and influenza virus and to determine whether detection of specific respiratory pathogens on NP samples was associated with ARI hospitalisation.

Methods: 349 children up to 5 years of age hospitalised for ARI (following a symptom-based case definition) and 306 hospital controls were prospectively enrolled in 16 centres across seven European Union countries between 2016 and 2019.

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Aims: Neuroferritinopathy (NF) or hereditary ferritinopathy (HF) is an autosomal dominant movement disorder due to mutation in the light chain of the iron storage protein ferritin (FTL). HF is the only late-onset neurodegeneration with brain iron accumulation disorder and study of HF offers a unique opportunity to understand the role of iron in more common neurodegenerative syndromes.

Methods: We carried out pathological and biochemical studies of six individuals with the same pathogenic FTL mutation.

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Neuromelanin is a complex polymer pigment found primarily in the dopaminergic neurons of human substantia nigra. Neuromelanin pigment is stored in granules including a protein matrix and lipid droplets. Neuromelanin granules are yet only partially characterised regarding their structure and function.

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Background: Insulin resistance and hyperglycaemia are common in severe sepsis. Mitochondrial uncoupling protein 2 (UCP2) plays a role in insulin release and sensitivity.

Objectives: To determine if a common, functional polymorphism in the UCP2 gene promoter region (the -866 G/A polymorphism) contributes to the risk of hyperglycaemia in severe sepsis.

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The m.8993T-->C MTATP6 mutation of mitochondrial DNA (mtDNA) usually causes mitochondrial disease in childhood, but was recently described in a family with adult onset ataxia and polyneuropathy. Cytochrome c oxidase muscle histochemistry, which is the standard clinical investigation for mitochondrial disease in adults, is usually normal in patients with MTATP6 mutations.

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The dysferlin gene is mutated in limb-girdle muscular dystrophy type 2B, Miyoshi myopathy, and distal anterior compartment myopathy. In mature skeletal muscle, dysferlin is located predominantly at the sarcolemma, where it plays a role in membrane fusion and repair. To investigate the role of dysferlin during early muscle differentiation, its localization was studied at high resolution in a muscle cell line.

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Aim: To investigate a possible association between mitochondrial haplogroups and primary open angle glaucoma (POAG).

Methods: Genomic DNA was extracted from 140 POAG patients and 75 healthy individuals. Restriction enzyme digest analysis of polymerase chain reaction (PCR) amplified fragments was used to determine the mitochondrial haplogroup of each patient and control.

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Mitochondrial DNA (mtDNA) mutations are a major cause of human disease. A large number of different molecular defects ultimately compromise oxidative phosphorylation, but it is not clear why the same biochemical defect can cause diverse clinical phenotypes. There is emerging evidence that nuclear genes modulate the phenotype of primary mtDNA disorders.

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Background: Human genome evolution has been shaped by infectious disease. Although most genetic studies have focused on the immune system, recovery after sepsis is directly related to physiological reserve that is critically dependent on mitochondrial function. We investigated whether haplogroup H, the most common type of mitochondrial DNA (mtDNA) in Europe, contributes to the subtle genetic variation in survival after sepsis.

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Recent evidence suggests that polymorphic genetic variation in the non-coding region of mitochondrial DNA (the 16184-16193 polycytosine [poly-C] tract) contributes to the cause of type 2 diabetes, but previous studies only just reached significance. We aimed to investigate this association. We compared patients with type 2 diabetes (n=992) with two independent control groups (n=536, n=1029) from the UK, and saw no difference in the frequency of the 16184-16193 poly-C tract.

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Objective: To determine the minimum prevalence of spinocerebellar ataxia type 17 (SCA17) in the north east of England.

Patients And Methods: A defined region containing 2,516,500 individuals with 192 families with undiagnosed ataxia, 90 patients with a Huntington's disease-like phenotype and 292 controls. The number of (CAG/CAA)(n) repeats in the SCA17/TBP gene was determined by fluorescent PCR and sequenced in affected individuals.

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Background: Primary open angle glaucoma (POAG) is considered to be a neurodegenerative optic neuropathy, in which cell death occurs by apoptosis. p21, is an important protective component of the apoptotic pathway, regulating cellular arrest in the presence of DNA damage. An unstable or altered p21 protein could modify the cellular response to genomic injury and abolish the effect of p21.

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There is increasing evidence that genetic variants of mitochondrial DNA have an important role in the cause of idiopathic Parkinson's disease. We determined the mitochondrial DNA haplogroup of 455 Parkinson's disease cases, 185 Alzheimer's disease cases, and 447 healthy English control subjects. The UKJT haplogroup cluster was associated with a 22% reduction in population-attributable risk for Parkinson's disease.

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The ENG1 Leber's hereditary optic neuropathy (LHON) family spans six generations and comprises more than 90 maternally related individuals. In this pedigree, the G:A LHON mutation at nucleotide position 11778 shows a complex pattern of segregation in which it is homoplasmic mutant in two branches, homoplasmic wildtype in another, and heteroplasmic in a fourth branch. In addition, there is co-segregation of the 11778 mutant allele and of a G:A silent polymorphism at nucleotide position 5471 in 18 of 19 family members.

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Purpose: Primary open angle glaucoma (POAG) is a major cause of late onset visual failure of unknown etiology. Recent genetic association studies have implicated the apolipoprotein E (APOE) gene in the pathophysiology of primary open angle glaucoma, but there have been conflicting findings.

Methods: To resolve this issue we studied 140 cases and 73 controls that were carefully phenotyped, and used a logistic regression model to simultaneously analyze the effect of apolipoprotein E genotype and functional polymorphisms in the apolipoprotein E gene promoter while controlling for potentially confounding variables.

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The authors describe an infant with a severe spastic paraparesis caused by two codominant mutations of the spastin gene. This highlights the multiple molecular mechanisms that are likely to be involved in the molecular pathology of SPG4 and illustrates the importance of complete screening of the spastin gene in affected individuals, particularly if the index case has an unusual phenotype.

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We performed a population-based clinical and molecular genetic study of spinocerebellar ataxia type 6 (SCA6) in the northeast of England. The minimum point prevalence of SCA6 was 1.59 in 100,000 (95% confidence interval [CI], 1.

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Objective: To test the hypothesis that genetic polymorphisms of the apolipoprotein E (APOE) gene are associated with primary open-angle glaucoma (POAG), based on the association between neurodegenerative diseases and the APOE genotype.

Methods: Genomic DNA was examined from an unrelated cohort of 137 POAG patients and 75 control subjects from the ophthalmology department of the Royal Victoria Infirmary. The APOE allele frequency (epsilon2, epsilon3, and epsilon4 alleles) was studied by polymerase chain reaction amplification of the related locus (19q13.

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Objective: Mutations in the skeletal muscle gene dysferlin cause two autosomal recessive forms of muscular dystrophy: Miyoshi myopathy (MM) and limb girdle muscular dystrophy type 2B (LGMD2B). The purpose of this study was to define the genomic organization of the dysferlin gene and conduct mutational screening and a survey of clinical features in 21 patients with defined molecular defects in the dysferlin gene.

Methods: Genomic organization of the gene was determined by comparing the dysferlin cDNA and genomic sequence in P1-derived artificial chromosomes (PACs) containing the gene.

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The SJL mouse strain has been widely used as an animal model for experimental autoimmune encephalitis (EAE), inflammatory muscle disease and lymphomas and has also been used as a background strain for the generation of animal models for a variety of diseases including motor neurone disease, multiple sclerosis and atherosclerosis. Recently the SJL mouse was shown to have myopathy due to dysferlin deficiency, so that it can now be considered a natural animal model for limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi myopathy (MM). We have cloned the mouse dysferlin cDNA and analysis of the sequence shows that the mouse dysferlin gene is characterized by six C2 domain sequences and a C-terminal anchoring domain, with the human and the mouse dysferlin genes sharing > 90% sequence homology overall.

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Dysferlin is the protein product of the gene (DYSF) that is defective in patients with limb girdle muscular dystrophy type 2B and Miyoshi myopathy. Calpain 3 is the muscle-specific member of the calcium activated neutral protease family and primary mutations in the CAPN3 gene cause limb girdle muscular dystrophy type 2A. The functions of both proteins remain speculative.

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Dysferlin, the protein product of the gene mutated in patients with an autosomal recessive limb-girdle muscular dystrophy type 2B (LGMD2B) and a distal muscular dystrophy, Miyoshi myopathy, is homologous to a Caenorhabditis elegans spermatogenesis factor, FER-1. Analysis of fer-1 mutants and of sequence predictions of the FER-1 and dysferlin ORFs has predicted a role in membrane fusion. Otoferlin, another human FER-1-like protein (ferlin), has recently been shown to be responsible for autosomal recessive nonsyndromic deafness (DFNB9).

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The cluster in Jews of Libyan origin of limb-girdle muscular dystrophy type 2B due to a dysferlin 1624delG mutation is described. The carrier frequency of this mutation is calculated to be approximately 10% in this population, in which the disease prevalence is at least 1 per 1300 adults. Twenty-nine patients from 12 families were all homozygous for the same mutation.

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