Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016719 (Friedreich's ataxia)
 2,098 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many metabolic diseases result in pathological changes within the cardiovascular system, often with the most severe effects on the function of the heart and great vessels. Metabolic disorders affecting the heart include disorders of amino acid metabolism, storage diseases, neuromuscular diseases, diseases of metal and pigment metabolism, carnitine deficiency, and connective tissue disorders. Several inborn errors of metabolism may involve the myocardium due to the accumulation of abnormal metabolites in the myocardial cells. In addition, the heart valves and coronary vessels may be involved. If the predominant effect is in the myocardial cell, it will be manifested clinically as a cardiomyopathy. Some disorders, in particular oxalosis, may involve the conduction system as a result of the deposition of oxalate crystals and result in conduction disturbances such as in alkaptonuria, primary oxalosis, and homocystinuria. Myocardial involvement may result in cardiomyopathy of the three functional types: (1) congestive, as in Fabry's disease, (2) hypertrophic, as in glycogen storage disease, type II, or (3) restrictive, as in Gaucher's disease. In the storage disease severe valvular as well as myocardial involvement occur predominantly in the glycogen storage diseases, types II-IV, mucolipidoses, sphingolipidoses, and neuronal ceroid lipofuscinosis. There are a variety of neuromuscular disorders that may be associated with cardiomyopathy, including the muscular dystrophies, Friedreich's ataxia, and Kugelberg-Welander syndrome. The pathological features of these conditions are not specific, but result usually in a congestive form of cardiomyopathy. Patients with metal and pigment metabolic disorders include iron storage disease, either hemochromatosis or transfusional hemosiderosis, Menkes' kinky hair syndrome, and Dubin-Johnson syndrome. Either a restrictive or a congestive form of cardiomyopathy may occur. The systemic form of carnitine deficiency is an autosomal recessive disorder and may present as a cardiomyopathy with congestive heart failure and lipid accumulation in the myocardial cells. Connective tissue disorders are generalized diseases that may involve the heart and valvular tissue, but also the blood vessels. These include Marfan's syndrome, Ehlers-Danlos syndrome, osteogenesis imperfecta, and pseudo-xanthoma elasticum.
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PMID:The effects of metabolic diseases on the cardiovascular system. 333 40

Excessive body iron or iron overload occurs under conditions such as primary (hereditary) hemochromatosis and secondary iron overload (hemosiderosis), which are reaching epidemic levels worldwide. Primary hemochromatosis is the most common genetic disorder with an allele frequency greater than 10% in individuals of European ancestry, while hemosiderosis is less common but associated with a much higher morbidity and mortality. Iron overload leads to iron deposition in many tissues especially the liver, brain, heart and endocrine tissues. Elevated cardiac iron leads to diastolic dysfunction, arrhythmias and dilated cardiomyopathy, and is the primary determinant of survival in patients with secondary iron overload as well as a leading cause of morbidity and mortality in primary hemochromatosis patients. In addition, iron-induced cardiac injury plays a role in acute iron toxicosis (iron poisoning), myocardial ischemia-reperfusion injury, Friedreich ataxia and neurodegenerative diseases. Patients with iron overload also routinely suffer from a range of endocrinopathies, including diabetes mellitus and anterior pituitary dysfunction. Despite clear connections between elevated iron and clinical disease, iron transport remains poorly understood. While low-capacity divalent metal and transferrin-bound transporters are critical under normal physiological conditions, L-type Ca2+ channels (LTCC) are high-capacity pathways of ferrous iron (Fe2+) uptake into cardiomyocytes especially under iron overload conditions. Fe2+ uptake through L-type Ca2+ channels may also be crucial in other excitable cells such as pancreatic beta cells, anterior pituitary cells and neurons. Consequently, LTCC blockers represent a potential new therapy to reduce the toxic effects of excess iron.
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PMID:Role of L-type Ca2+ channels in iron transport and iron-overload cardiomyopathy. 1660 32

The traditional role of iron chelation therapy has been to reduce body iron burden via chelation of excess metal from organs and fluids and its excretion via biliary-fecal and/or urinary routes. In their present use for hemosiderosis, chelation regimens might not be suitable for treating disorders of iron maldistribution, as those are characterized by toxic islands of siderosis appearing in a background of normal or subnormal iron levels (e.g., sideroblastic anemias, neuro- and cardio-siderosis in Friedreich ataxia- and neurosiderosis in Parkinson's disease). We aimed at clearing local siderosis from aberrant labile metal that promotes oxidative damage, without interfering with essential local functions or with hematological iron-associated properties. For this purpose we introduced a conservative mode of iron chelation of dual activity, one based on scavenging labile metal but also redeploying it to cell acceptors or to physiological transferrin. The "scavenging and redeployment" mode of action was designed both for correcting aberrant iron distribution and also for minimizing/preventing systemic loss of chelated metal. We first examine cell models that recapitulate iron maldistribution and associated dysfunctions identified with Friedreich ataxia and Parkinson's disease and use them to explore the ability of the double-acting agent deferiprone, an orally active chelator, to mediate iron scavenging and redeployment and thereby causing functional improvement. We subsequently evaluate the concept in translational models of disease and finally assess its therapeutic potential in prospective double-blind pilot clinical trials. We claim that any chelator applied to diseases of regional siderosis, cardiac, neuronal or endocrine ought to preserve both systemic and regional iron levels. The proposed deferiprone-based therapy has provided a paradigm for treating regional types of siderosis without affecting hematological parameters and systemic functions.
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PMID:Regional siderosis: a new challenge for iron chelation therapy. 2442 36