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Stephen J. Boyer - One of the best experts on this subject based on the ideXlab platform.

Ikuya Nonaka - One of the best experts on this subject based on the ideXlab platform.

  • Central Core disease and congenital neuromuscular disease with uniform type 1 fibers in one family.
    Brain & development, 2000
    Co-Authors: Megumu Tojo, Matsuko Ozawa, Ikuya Nonaka
    Abstract:

    We report a family in which the father had Central Core disease and his son had congenital neuromuscular disease with uniform type 1 fibers. This is the first report of such a combination. Although they had no recognized mutation in the ryanodine receptor gene, it is highly likely that the son also had Central Core disease but without Core structures. The absence of Cores may be due to the muscle sample or the young age of the patient since Core structures have been reported to increase with age. Although the prevalence of Core structures in individual muscles is unknown, there is a possibility of sampling error. In some patients, congenital neuromuscular disease with uniform type 1 fibers is closely related to or identical with Central Core disease.

  • Scoliosis associated with Central Core disease.
    Brain & development, 1994
    Co-Authors: Toshiro Nagai, Yutaka Tsuchiya, Akiko Maruyama, Masakazu Takemitsu, Ikuya Nonaka
    Abstract:

    Abstract A 12-year-old Japanese girl who had progressive severe scoliosis but with minimal muscle weakness in the extremities was found to have Central Core disease. In her muscle biopsies obtained from the biceps brachii and paraspinous muscles, there was type 1 fiber atrophy and predominance, as is commonly seen in congenital myopathies, but the Core structure was identified only in the former. To determine whether scoliosis is a prominent feature of this disease, we reviewed 10 patients with Central Core disease in our laboratory and found 6 ambulant patients who had mild-to-moderate scoliosis. Since kyphoscoliosis becomes prominent as muscle weakness progresses to loss of ambulation in most muscle diseases, this disproportionate spinal involvement in Central Core disease appears to be a striking feature. All patients with ‘idiopathic’ scoliosis deserve a careful neurological evaluation, even if they have minimal muscle symptoms in the extremities.

Caroline Sewry - One of the best experts on this subject based on the ideXlab platform.

  • Central Core myopathy with RYR1 mutation masks 5q Spinal Muscular Atrophy
    European journal of paediatric neurology : EJPN : official journal of the European Paediatric Neurology Society, 2010
    Co-Authors: R. Pandey, Caroline Sewry, J.s.m. Dwyer, S. Chandratre, A.p. Roberts, Ros Quinlivan
    Abstract:

    We report the case of a male who presented in infancy with motor delay and muscle weakness. Typical muscle biopsy features and heterozygous RYR1 mutation confirmed a diagnosis of Central Core disease. Family studies showed this to be a de-novo mutation. Some years later, his two older teenage brothers presented with proximal muscle weakness. Neurophysiology, muscle biopsy and DNA studies confirmed spinal muscular atrophy. Subsequent genetic studies in the index case also confirmed homozygous deletions of exon 7 and 8 in the SMN gene. Review of the original muscle biopsy showed classical features of Central Core disease with no evidence to suggest denervation, such that the diagnosis of spinal muscular atrophy could not have been suspected in the absence of the family history.

  • Central Core disease: clinical, pathological, and genetic features
    Archives of disease in childhood, 2003
    Co-Authors: Ros Quinlivan, Clemens R. Müller, Mark R. Davis, J.s.m. Dwyer, J. Dove, G.a. Evans, Nigel G. Laing, A.p. Roberts, Caroline Sewry
    Abstract:

    Central Core disease (CCD) is a dominantly inherited congenital myopathy allelic to malignant hyperthermia (MH) caused by mutations in the RYR1 gene on chromosome 19q13.1. Eleven individuals with RYR1 mutations are described. Four index cases showed features consistent with a congenital myopathy (hypotonia, delayed motor milestones, and skeletal abnormalities including congenital hip dislocation and scoliosis). All four cases and subsequently seven other family members were found to possess novel mutations in the RYR1 gene. The degree of disability varied from one clinically normal individual, to another who had never achieved independent ambulation (the only patient with a de novo mutation). Four cases showed a mild reduction in vital capacity, repeated nocturnal polysomnography showed hypoxaemia in one case. A variety of muscle biopsy features were found; Central Cores were absent in the youngest case, and the biopsy specimens from two others were more suggestive of mini-Core myopathy. In all cases missense mutations in exons 101, 102, and 103 of the RYR1 gene on were found. Future laboratory diagnosis of suspected cases and family members will be less invasive and more accurate with DNA analysis. Clinicians, especially paediatricians and orthopaedic surgeons, should be aware of this disorder because of the potential risk of MH.

  • Central Core disease: new findings in an old disease.
    Brain, 2003
    Co-Authors: F. Muntoni, Caroline Sewry
    Abstract:

    Central Core disease (CCD) is a clearly defined clinical condition with striking pathological changes that facilitate the diagnosis. The condition was first reported in 1956 by Shy and Magee (1956) who described a dominant family in which muscle fibres had a Central area devoid of oxidative enzyme activity. They named the disorder Central Core disease, after this histopathological feature. Since then many similar cases have been identified, confirming that this is a distinct disorder. Relatively little happened between 1956 and 1990, when linkage to chromosome 19q.13 was established, followed in 1993 by the identification of mutations in the ryanodine receptor gene ( RYR1 ). Mutations in the same gene also occur in patients with malignant hyperthermia susceptibility (MHS) (McCarthy et al ., 2000), some of whom show Core lesions, although they may have no muscle weakness. The large size of the RYR1 gene (106 exons) has made it difficult to study large populations of patients and establish a genotype–phenotype correlation. However, significant pathological and molecular advances have recently been made. We now know that cases with eccentric or peripheral Cores, and/or multiple miniCores, or cases showing only uniformity of type 1 fibres with an absence of Cores, or cases with only mild unevenness of oxidative enzyme staining, or cases with marked muscle replacement by fatty tissue in association …

  • The spectrum of pathology in Central Core disease.
    Neuromuscular disorders : NMD, 2002
    Co-Authors: Caroline Sewry, Clemens R. Müller, Mark R. Davis, J.s.m. Dwyer, J. Dove, G.a. Evans, Rolf Schröder, Dieter O. Fürst, Timothy R. Helliwell, Nigel G. Laing
    Abstract:

    Abstract Central Core disease is a congenital myopathy with muscle weakness defined pathologically by the presence of extensive areas in muscle fibres that are devoid of oxidative enzyme activity. The gene responsible has been shown to be the ryanodine receptor 1 on chromosome 19q13 and mutations have now been identified in several patients. Some cases with the morphological defect remain molecularly undefined, particularly those studied before molecular studies were available. We have studied three families with congenital onset, each with a dominantly inherited mutation in a C-terminal exon of the ryanodine receptor 1. They illustrate the spectrum of pathology that can be observed in patients with the myopathic features of Central Core disease. We show that extensive fibrosis and fat may be present, type 1 fibre uniformity may occur in the absence of Cores; Cores may be Central or peripheral, single or multiple; and that an appearance of multiple focal miniCores might cause a diagnostic pathological dilemma. In addition, we show the value of immunocytochemistry in identifying Cores, in particular the use of antibodies to desmin and γ-filamin.

  • A severe clinical and pathological variant of Central Core disease with possible autosomal recessive inheritance
    Neuromuscular disorders : NMD, 1998
    Co-Authors: Adnan Y. Manzur, Caroline Sewry, J. Ziprin, Victor Dubowitz, F. Muntoni
    Abstract:

    Central Core disease (CCD) is a well recognized, relatively mild, non- or slowly progressive, dominantly inherited, congenital myopathy due, at least in some families, to mutations in the ryanodine receptor gene on chromosome 19q13.1. We report two unrelated cases with an unusual, early onset congenital myopathy with severe contractures, delayed motor milestones, proximal muscle weakness, normal serum creatine kinase (CK), a non-progressive course, with muscle biopsy findings of Central Cores and in addition, marked proliferation of connective and adipose tissue, and variation in fibre size. Muscle biopsies from the parents, who were non-consanguineous and healthy, showed minor myopathic changes and uneven staining with oxidative enzymes, but no Central Cores. The marked histological muscle changes, the distribution of weakness and the non-progressive course of the disease suggest that this is a severe variant of Central Core disease with secondary dystrophy-like change. The presence of mild changes in the histochemical reactions of biopsies of both parents of these two children supports the hypothesis that they are carriers of a recessive disease gene mutation responsible for this unusually severe form of Central Core disease.

James W. Leahy - One of the best experts on this subject based on the ideXlab platform.

Marco Rogna - One of the best experts on this subject based on the ideXlab platform.

  • The Central Core and the Mid-Central Core as Novel Set-valued and Point-valued Solution Concepts for TU Coalitional Games: Topological and Axiomatic Properties
    2017
    Co-Authors: Marco Rogna
    Abstract:

    The present paper proposes two new solution concepts that are Core restrictions: the first, set-valued, is the Central Core, the second, point valued, is the Mid-Central Core. The basic idea at the root of the Central Core is to allow such Core elements that grant to each player at least the pay-off obtained as the centroid of the extreme points of the set of endogenous outside options that would emerge from a hypothetical bargaining game over the same coalitions except the grand coalition. The Mid-Central Core is simply defined as the centroid of the extreme points of the Central Core. The basic topological properties of the Central Core are then analysed showing that it is a convex polytope with dimensionality equal to, maximum, n-2 and, at most, n extreme points lying on the boundaries of the Core, with $n$ being the number of players in the coalitional game. It is further shown that almost all axiomatic properties of the Core are preserved by these restrictions, except for consistency. The Mid-Central Core further satisfies aggregate and weak coalitional monotonicity, but not strong and coalitional monotonicity.

  • The Central Core and the mid-Central Core as novel set-valued and point-valued solution concepts for transferable utility coalitional games
    Mathematical Social Sciences, 1
    Co-Authors: Marco Rogna
    Abstract:

    Abstract This paper proposes two new solution concepts for transferable utility coalitional games that are Core selections, the Central Core and the Mid-Central Core, with the first being set-valued and the latter point-valued. The basic idea at the root of the Central Core is to allow such Core elements that grant to each player at least the pay-off obtained from the centroid of the extreme points of the Core of the same game but with the worth of the grand coalition reduced to the minimum value such that the game remains balanced. The Mid-Central Core is defined as the centroid of the extreme points of the Central Core. Some basic geometrical properties of the Central Core are then analysed, showing that it is a convex polytope that coincides with the Core under particular circumstances, or it is a strict subset of the Core. It is further shown that almost all fundamental axiomatic properties of the Core are preserved by these solutions. Finally, an axiomatization of the Mid-Central Core is provided through the adaptation of the mid-point domination property to a coalitional setting. The Mid-Central Core is the only solution satisfying individual and group rationality together with aggregate monotonicity and a version of mid-point domination whose reference set is shaped according to the mentioned axioms.