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Diseases of the Peripheral Nerve and Mononeuropathies
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Diana Mnatsakanova, Charles K. Abrams
Three forms associated with neuropathy: Acute intermittent porphyria (AIP): porphobilinogen deaminase deficiency.Hereditary coproporphyria (HCP): defects in coproporphyrin oxidase.Variegate porphyria (VP): impaired protoporphyrinogen oxidase.
Sideroblastic Anemia and Porphyrias
Published in Harold R. Schumacher, William A. Rock, Sanford A. Stass, Handbook of Hematologic Pathology, 2019
Variegate porphyria is caused by a deficiency of activity of protoporphyrinogen oxidase, and is common in South Africa. Clinically, patients with the disease demonstrate acute neuro-logic symptoms and photodermatitis. In variegate porphyria, increased amount of protoporphyrin occur in the stool. For acute attacks, glucose, chlorpromazine, and intravenous heme are used.
Medical (Madness)—Mistakes Throughout History
Published in Miner Gary, Miner Linda, Dean Darrell, Healthcare’s Out Sick – Predicting A Cure – Solutions That Work !!!!, 2019
Miner Gary, Miner Linda, Dean Darrell
Various authors looking back at his documented symptoms have given several plausible explanations for King George’s illness, which occurred in bouts from 1788 until his death, with the last ten years of his life being his sickest. One explanation or diagnosis involved bipolar disorder based on his writings during his “manic” periods (BBC News, April 15, 2013, http://www.bbc.com/news/magazine-22122407; Peters and Beveridge, 2010, https://www.ncbi.nlm.nih.gov/pubmed/20503691). Variegate porphyria was suspected due to the reported blue color of King George’s urine and because some of the symptoms of porphyria are like untreated bipolar disorder. However, that hypothesis was initially withdrawn once it was realized that the medicine provided by one of his physicians was made from deep blue flowers, which colored his urine naturally. Another theory, poisoning, was raised when, in 2005, arsenic was found in a saved lock of his hair. A lock of King George’s hair on display at the Science Museum in London was used for analysis.
Givosiran, a novel treatment for acute hepatic porphyrias
Published in Expert Review of Precision Medicine and Drug Development, 2021
Manish Thapar, Sean Rudnick, Herbert L. Bonkovsky
The human porphyrias generally are classified according to the principal sites of overproduction of porphyrins or porphyrin precursors as being either hepatic or erythropoietic. The hepatic porphyrias are further classified as being ‘acute’ or ‘inducible’ (due to up-regulation of ALA synthase-1) or as being ‘chronic.’ The acute designation is used for four relatively rare disorders, all due to inherited defects in normal heme synthesis [ALA dehydratase deficient porphyria (ADP); acute intermittent porphyria (AIP), due to partial deficiency of HMBS; hereditary coproporphyria (HCP), due to partial deficiency of CPOX; and variegate porphyria (VP), due to partial deficiency of PPOX]. When these are biochemically active (elevated ALA and PBG), there is induction of ALA synthase-1 in the liver, as already described, leading to marked overproduction of ALA, and usually also of porphobilinogen (PBG). The chronic hepatic porphyrias comprise two disorders, porphyria cutanea tarda (PCT) and hepatoerythropoietic porphyria (HEP), which, respectively, are due to partial (∼50%) or nearly total (>90%) deficiency of uroporphyrinogen decarboxylase (UROD), the fifth enzyme of the heme synthetic pathway. PCT, the disorder with milder UROD deficiency, occurs mainly in adult men with underlying liver disease, whereas the disorder with severe UROD deficiency is HEP. It is usually manifest in childhood or infancy and continues life-long.
Neurological and neuropsychiatric manifestations of porphyria
Published in International Journal of Neuroscience, 2019
Yiji Suh, Jason Gandhi, Omar Seyam, Wendy Jiang, Gunjan Joshi, Noel L. Smith, Sardar Ali Khan
Porphyria refers to a group of disorders that results from a defect in the heme biosynthetic pathway. Most heme in mammals is produced in erythroid cells. The central and peripheral nervous systems may be affected as well as various other organ systems. The subtypes of porphyria can be categorized as hereditary coproporphyria (HC), acute intermittent porphyria (AIP), variegate porphyria (VP) and porphyria cutanea tarda. Not all types cause neurologic problems. HC, AIP and VP are hepatic pathologies with neurologic manifestations that are inherited in an autosomal dominant pattern [1]. Porphyria cutanea tarda, which is the most common among patients, and erythropoietic protoporphyria are not neurologic, but have cutaneous manifestations [2]. A physician should suspect porphyria if the patient has motor-predominant peripheral neuropathy, gastrointestinal distress, dermatologic, and neuropsychiatricrelated complications. According to Anderson et al., porphyria occurs in about 0.5 to 10 per 100,000 people [2].
Porphyrias and photosensitivity: pathophysiology for the clinician
Published in Postgraduate Medicine, 2018
Loukas Kakoullis, Stylianos Louppides, Eleni Papachristodoulou, George Panos
Porphyrias manifest with either one or more of these clinical syndromes, depending of the substrates being accumulated. Acute intermittent porphyria (AIP) manifests as acute neurovisceral disease only, hereditary coproporphyria (HCP), and variegate porphyria (VP) combine acute neurovisceral disease with delayed blistering photosensitivity, whereas porphyria cutanea tarda (PCT) and congenital erythropoietic porphyria (CEP) manifest only as delayed blistering photosensitivity. However, it should be noted that photosensitivity in CEP is far more severe and can lead to photomutilation and disfigurement. Immediate and painful photosensitivity characterizes the two forms of protoporphyria, erythropoietic protoporphyria (EPP) and X-linked erythropoietic protoporphyria (XLEPP) [7,9,11]. Finally, an ultra-rare form of porphyria, ALA dehydratase deficiency porphyria (ALADP), manifests with acute neurovisceral disease, but due to the paucity of reported cases (less than 10 cases have been reported [7]), the complete range of its manifestations remains unknown [11], and thus will not be discussed. The main source of heme precursors in AIP, PCT, HCP, and VP is the liver, whereas the bone marrow produces the excess of porphyrins observed in CEP, EPP and XLEPP [7]. In hepatoerythropoietic porphyria, another ultra-rare form of porphyria, both the liver and bone marrow contribute to the excess production of heme precursors [12,13].