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Systemic Illnesses (Diabetes Mellitus, Sarcoidosis, Alcoholism, and Porphyrias)
Published in Jacques Corcos, Gilles Karsenty, Thomas Kessler, David Ginsberg, Essentials of the Adult Neurogenic Bladder, 2020
Porphyrias consist of a group of eight metabolic hereditary disorders. They are further classified as either erythropoietic or hepatic depending on the main site of expression of the defective enzyme. The disease is caused by acquired or inherited partial deficiency of one of the enzymes in heme biosynthesis. Porphyrin precursor's overproduction is seen in acute hepatic porphyrias, whereas porphyrins are seen in the cutaneous types.34 There are five hepatic porphyrias, four of which present with neurologic symptoms: acute intermittent porphyria (AIP), δ-aminolevulinic acid dehydratase-deficient porphyria (ADP), hereditary coproporphyria (HCP), and variegate porphyria (VP).35 Acute attacks are usually precipitated by factors that fall into four categories: nutrition, endocrine factors, stress, and drugs. The consumption of various drugs includes, but is not limited to, contraceptives, barbiturates, sulfonamides, griseofulvin, phenytoin, valproic acid, steroids, and succinimides.
Medicine
Published in Seema Khan, Get Through, 2020
Synthesis of heme, an important constituent of haemoglobin, occurs in the liver. The process is complex in which a large number of enzymes are needed at each step to convert haem precursors (known as porphyrins) into haem itself. Enzyme deficiency can occur at any step of the process leading to accumulation of porphyrins and to symptoms of porphyria. Porphyria is in fact a group of disorders which includes acute intermittent porphyria, cutaneous porphyria and mixed porphyria. Drugs, particularly those containing hormones (e.g. the pill or HRT), infections, smoking and alcohol are known precipitants.
Blistering diseases in the elderly
Published in Robert A. Norman, Geriatric Dermatology, 2020
The diagnosis of porphyria should be made after screening urine and blood for porphyrins64. The total amount of porphyrins excreted in 24 hours in usually greater than 1000 micrograms64. The urine is examined with a Wood’s lamp and exhibits a reddish-pink color if PCT is present. Elevated levels of iron, ferritin and transaminases in serum are also seen in PCT62,63.
Organophosphate insecticide poisoning with monocrotophos-induced fabricated illness in a 7-year-old girl with refractory seizures over a 4-year period
Published in Paediatrics and International Child Health, 2022
Chisambo Mwaba, Chalilwe Chungu, Ronald Chola, Kafula Lisa Nkole, Somwe Wa Somwe, Evans Mpabalwani
Between the scheduled clinic visits, the patient continued to present episodes in which she was lethargic, was unable to walk or talk, and had abdominal pain, nausea and vomiting. She also passed red urine intermittently. A diagnosis of porphyria was again considered. However, funds for a repeat urine porphyrin test were not available. Over this period, the ASM was changed to increasing doses of gabapentin and then later to levetiracetam in an attempt to achieve better seizure control. In addition, during the course of the last of the above four admissions, the child developed a right femoral deep vein thrombosis (DVT) associated with a central line which was required for dextrose infusions. She had been discharged home on anticoagulants 3 weeks before her fifth and final admission to the HDW.
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 porphyrias are a group of disorders, mainly due to inborn errors of metabolism, in which the primary defects are in normal heme synthesis. The principal sites of heme synthesis in vertebrates are the bone marrow (developing erythrocytes) and the liver (hepatocytes), which have high levels of cytochromes P-450 (CYP), the principal users of hepatic heme. Figure 1 shows an overview of the normal pathway of mammalian heme synthesis, which requires the coordinated, sequential functioning of eight enzymes, beginning with 5-aminolevulinic acid (ALA) synthase, which carries out the condensation of glycine and succinyl CoA to form ALA, and ending with ferrochelatase (FECH) or heme synthase, which inserts divalent iron into protoporphyrin IX to form heme. ALA synthase is normally the rate-controlling enzyme of the entire pathway, and, in the liver and likely most other non-erythropoietic organs, its activity is tightly controlled by the availability of heme. Thus, hepatic ALA synthase (also known as ALA synthase-1 or the housekeeping form of ALA synthase), and the entire pathway is subject to end-product repression [1].
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].