Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026850 (muscular dystrophy)
 5,870 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recognition and application of blood group differences on human red cells permitted the development of safe procedures for blood transfusion. Blood group antigens are markers on surface-exposed red cell proteins or the sugar moiety of glycoproteins or glycolipids. Apart from their presumed biological function, some antigens have been identified as receptors for host/parasite interactions. Thus, carbohydrates that determine P antigenicity are the binding receptor for certain strains of pyelonephritic coliforms. Other pathogenic coliforms bind to the membrane structure that carries the Dra antigen. A structure associated with Duffy antigens is the attachment receptor for the parasite of Plasmodium vivax malaria, while Plasmodium falciparum parasites bind to structures associated with membrane glycophorins. Structure/function relationships have been established by the finding that lack of Rh protein in red cells of Rhnull phenotype is associated with stomatocytic cell morphology and a hemolytic state. Absence of glycophorin C, and the Gerbich blood group antigens that it carries, is associated with elliptocytic red cells. Absence of Kx antigen protein in the Kell system is associated with the McLeod blood group phenotype, with acanthocytic cell morphology and reduced in vivo survival. McLeod individuals also have late-onset muscular dystrophy and neurological disorders.
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PMID:Biological roles of blood group antigens. 229 4

A 51-year-old man developed weakness and muscle atrophy in the legs at the age of 41, later followed by choreiform involuntary movements. Neurological and laboratory examinations revealed severe muscle weakness and atrophy, and areflexia in all the extremities, acanthocytosis and an elevated serum creatine kinase level. Together with these findings, the weak expression of Kell blood group antigens and the absence of the Kx antigen led to a definite diagnosis of McLeod syndrome for his condition. Brain magnetic resonance imaging revealed marked atrophy of the head of the caudate nuclei. Although immunocytochemical analysis of dystrophin in muscle specimens from our patient revealed normal staining, we found prominent fiber size variability, central nuclei, and connective tissue proliferation as well as necrotic and regenerating fibers, which are as a whole compatible with the myopathology of muscular dystrophy. Moreover, muscle computerized tomography of the lower extremities revealed the 'selectivity pattern' characteristically reported in muscular dystrophies including Duchenne type muscular dystrophy. The muscular symptoms and pathology in McLeod syndrome have been reported to be mild, but the present case clearly shows that the muscular features in this condition may be much more severe than previously thought.
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PMID:A case of McLeod syndrome with unusually severe myopathy. 1046 97

Two membrane proteins express the antigens that comprise the Kell blood group system. A single antigen, Kx, is carried on XK, a 440-amino acid protein that spans the membrane 10 times, and more than 20 antigens reside on Kell, a 93-kd, type II glycoprotein. XK and Kell are linked, close to the membrane surface, by a single disulfide bond between Kell cysteine 72 and XK cysteine 347. Although primarily expressed in erythroid tissues, Kell and XK are also present in many other tissues. The polymorphic forms of Kell are due to single base mutations that encode different amino acids. Some Kell antigens are highly immunogenic and may cause strong reactions if mismatched blood is transfused and severe fetal anemia in sensitized mothers. Antibodies to KEL1 may suppress erythropoiesis at the progenitor level, leading to fetal anemia. The cellular functions of Kell/XK are complex. Absence of XK, the McLeod phenotype, is associated with acanthocytic red blood cells (RBCs), and with late-onset forms of muscular dystrophy and nerve abnormalities. Kell, by homology, is a member of the neprilysin (M13) family of membrane zinc endopeptidases and it preferentially activates endothelin-3 by specific cleavage of the Trp21-Ile22 bond of big endothelin-3.
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PMID:The Kell blood group system: Kell and XK membrane proteins. 1079 80

The authors describe a family with six patients with muscular dystrophy with a variable course. One is a compound heterozygote for CAPN3 mutations (calpainopathy) and the others have a single CAPN3 mutation. Linkage analysis and sequencing revealed a XK gene mutation (McLeod syndrome). This illustrates the variable phenotype of XK mutations and suggests the possibility that CAPN3 heterozygotes may have their condition caused by nonallelic mutations in other unrelated genes.
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PMID:A family with McLeod syndrome and calpainopathy with clinically overlapping diseases. 1634 36

With improved screening of patients with primary and secondary myopathies and more comprehensive investigations it turns out that an increasing number of patients with myopathies develops cardiac disease (cardiac involvement), before or after onset of the neuromuscular abnormalities. Cardiac involvement in myopathies manifests within the myocardium or the cardiac conduction system with impulse generation or conduction disturbances. An increasingly recognized rhythm abnormality in these patients is atrial fibrillation/flutter (AFI/AFL), which carries an increased risk for stroke embolism and represents an absolute indication for oral anticoagulation (OAC). Primary myopathies, in which AFI/AFL has been described so far include dystrophinopathies, Emery-Dreifuss muscular dystrophy, facio-scapulo-humeral muscular dystrophy, limb girdle muscular dystrophies, congenital myopathies, myofibrillar myopathies, myotonic dystrophies, glycogenoses, mitochondrial disorders, Barth syndrome, McLeod syndrome, and non-specific myopathies. Secondary myopathies, in which AFI/AFL has been described comprise polymyositis, dermatomyositis, colchicine-induced myopathy, and hyperthyroid myopathy. Myopathies most commonly associated with AFI/AFL are myotonic dystrophy and Emery-Dreifuss muscular dystrophy. Information about the frequency of stroke/embolism in these patients is rudimentary but there are indications that it is not increased in these patients. Only a few patients with AFI/AFL receive OAC to prevent from stroke/embolism. Patients with myopathy and AFI/AFL require thorough surveillance. If additional cardiovascular risk factors develop, OAC should be considered as in patients with other causes of AFI/AFL.
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PMID:Atrial fibrillation/flutter in myopathies. 1834 11