Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.5.1.61 (porphobilinogen deaminase)
637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Acute intermittent porphyria mimics a variety of commonly occurring disorders and thus poses a diagnostic quagmire. Psychiatric manifestations include hysteria, anxiety, depression, phobias, psychosis, organic disorders, agitation, delirium, and altered consciousness ranging from somnolence to coma. Some patients develop psychosis similar to schizophrenia. Psychiatric hospitals have a disproportionate number of patients with this disorder as only difficult and resistant patients accumulate there. Presence of photosensitive porphyrins in the urine is diagnostic. When porphyrins are absent, excess of alpha aminolevulinic acid and porphobilinogen are present in the urine. The definitive test is to measure monopyrrole porphobilinogen deaminase in RBCs. This diagnosis should be entertained in the following situations: (a) unexplained leukocytosis; (b) unexplained neuropathy; (c) etiologically obscure neurosis or psychosis; (d) 'idiopathic' seizure disorder; (e) unexplained abdominal pain; (f) conversion hysteria, and (g) susceptibility to stress. Porphyria is important in psychiatry as it may present with only psychiatric symptoms; it may masquerade as a psychosis and the patient may be treated as a schizophrenic person for years; the only manifestation may be histrionic personality disorder which may not receive much attention. Diagnosis is based on a high index of suspicion and appropriate investigation. Various psychotropic drugs exacerbate acute attacks. While it is important not to use the unsafe drugs in porphyric patients, it is also imperative to look for this diagnosis in cases where these drugs produce unprecedented drug reactions.
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PMID:Porphyria: reexamination of psychiatric implications. 865 42

Patients with acute intermittent porphyria can be subdivided into three groups, according to the porphobilinogen deaminase activity in their erythrocytes. The first group has lowered, the second overlapping and the third normal porphobilinogen deaminase activity. Of 385 acute intermittent porphyria patients 5% had normal porphobilinogen deaminase activity. Gene carriers of acute intermittent porphyria, which have normal porphobilinogen deaminase activity but display slight, moderate or high aberrations of excretion, are recognized by analysis of urinary haem precursors and faecal porphyrins. Six individuals suffering from acute intermittent porphyria were detected in three families with normal porphobilinogen deaminase. There were no differences in the latent and clinical phases of acute intermittent porphyria between patients with lowered and those with normal porphobilinogen deaminase. One female with normal activity in erythrocytes, in which the porphyria disease process is triggered by barbiturates and carbamazepine, is presented. After therapy with high doses of glucose and omission of inducing agents, this woman was free of symptoms, and the excretion of different urinary porphyrin precursors and porphyrins decreased by between 65 and 93%.
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PMID:Heterogeneity of acute intermittent porphyria: a subtype with normal erythrocyte porphobilinogen deaminase activity in Germany. 887 36

A 58-year-old woman gave a 6-month history of porphyria-like photosensitivity. Fractioned porphyrin analysis by high performance liquid chromatography revealed elevated concentrations of all urinary porphyrins and faecal protoporphyrin. Hepatocellular carcinoma had developed in an otherwise normal liver. Tumour tissue fluoresced strongly under fluorescence microscopy, exhibiting elevated activity of three haem-biosynthetic enzymes, delta-aminolevulinic acid (ALA) synthase. ALA dehydratase and porphobilinogen deaminase. This patient did not satisfy any of the criteria for inherited porphyria. The patient's symptoms were relieved after excision of the liver tumour. This strongly suggests that excessive porphyrin synthesis originated from the tumour tissue. Primary porphyria-like photosensitivity occurs as a paraneoplastic phenomenon, secondary to hepatocellular carcinoma.
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PMID:Symptomatic porphyria secondary to hepatocellular carcinoma. 903 12

Acute intermittent porphyria, the most commun acute porphyria in France, is an autosomal dominant disorder of heme biosynthesis. The basic biochemical defect is reduced activity of the enzyme porphobilinogen deaminase. Clinical evolution is characterized by acute attacks, with a severe prognosis due to acute abdominal pain and risk of neurological complications, induced by drug intake, infection, alcohol intake or unknown factors. We report the case of a patient with an inappropriate antidiuretic secretion syndrome and secondary hyperaldosteronism associated with acute intermittent porphyria and polyradiculoneuritis syndrome. This syndrome was found to be induced a delayed reaction to thiopental. A favorable response was achieved with heme-arginate treatment.
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PMID:[Acute intermittent porphyria associated with hyperaldosteronism and inappropriate antidiuretic hormone secretion syndrome]. 982 63

Acute porphyrias are inherited disorders caused by partial deficiency of specific heme biosynthesis enzymes. Clinically, porphyrias are manifested by a neuropsychiatric syndrome that includes peripheral neuropathy. Although much is known about the porphyrias' enzyme defects and their biochemical consequences, the cause of the neurological manifestations remains unresolved. We have studied porphyric neuropathy in mice with a partial deficiency of porphobilinogen deaminase (PBGD). PBGD-deficient mice (PBGD-/-) imitate acute porphyria through massive induction of hepatic delta-aminolevulinic acid synthase by drugs such as phenobarbital. Here we show that PBGD-/- mice develop impairment of motor coordination and muscle weakness. Histologically femoral nerves of PBGD-/- mice exhibit a marked decrease in large-caliber (>8 microm) axons and ultrastructural changes consistent with primary motor axon degeneration, secondary Schwann cell reactions, and axonal regeneration. These findings resemble those found in studies of affected nerves of patients with acute porphyria and thus provide strong evidence that PBGD deficiency causes degeneration of motor axons without signs of primary demyelination, thereby resolving a long-standing controversy. Interestingly, the neuropathy in PBGD-/- mice developed chronically and progressively and in the presence of normal or only slightly (twofold) increased plasma and urinary levels of the putative neurotoxic heme precursor delta-aminolevulinic acid. These data suggest that heme deficiency and consequent dysfunction of hemeproteins can cause porphyric neuropathy.
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PMID:Motor neuropathy in porphobilinogen deaminase-deficient mice imitates the peripheral neuropathy of human acute porphyria. 1020 64

Acute intermittent porphyria (AIP), the most common hepatic porphyria, results from the half-normal activity of hydroxymethylbilane synthase (HMB-synthase; EC 4.3.1.8), the third enzyme in the heme biosynthetic pathway. Because life-threatening acute neurologic attacks of this autosomal dominant disease are triggered by various ecogenic factors (e.g., certain drugs, hormones, alcohol, and starvation), efforts have been directed to identify and counsel presymptomatic heterozygotes in affected families to avoid the precipitating factors. Thus, to determine the nature of the mutations causing AIP in 26 unrelated enzyme-confirmed patients from Argentina, a long-range polymerase chain reaction method was developed to amplify the entire 10-kb gene in two fragments for efficient cycle sequencing and mutation detection. Eight new mutations were identified including two missense mutations (Q34P and G335S), four small deletions (728delCT, 815delAGGA, 948delA, and 985del12), a single base insertion (666insA), and a splice site mutation (IVS12(+1)). In addition, five previously reported mutations (G111R, R173W, Q204X, R201W, and 913insC) were detected. Notably, G111R was identified in 12 of the 26 (46%) presumably unrelated propositi; however, haplotype analysis with intragenic and flanking markers indicated an ancestral founder. Expression of the two new missense mutations (Q34P and G335S) in f1 E. coli resulted in 2.5% or less of the normal expressed enzyme, confirming their defective function. Thus, eight new and five previously reported HMB-synthase mutations, including a common lesion, were detected, permitting accurate identification and counseling of presymptomatic carriers in these 26 unrelated Argentinean AIP families with this dominant porphyria.
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PMID:Identification and characterization of hydroxymethylbilane synthase mutations causing acute intermittent porphyria: evidence for an ancestral founder of the common G111R mutation. 1049 93

Acute intermittent porphyria (AIP) is an autosomal dominant inherited disease caused by a decreased activity of hydroxymethylbilane synthase (HMBS). Regarding the abnormalities of the HMBS gene, many different mutations have been reported worldwide; however, few families from Japan have been studied. In this work, we investigated the presence of mutations in two unrelated Japanese patients with AIP. Mutational analysis was performed using the polymerase chain reaction-single strand conformation polymorphism (SSCP) method, followed by DNA sequencing. Reliable restriction enzyme cleavage assays were also established for the pedigree analyses. Unique SSCP patterns were noted in exons 12 and 15 of the HMBS gene. Sequencing revealed different mutations in each patient: a two-base deletion of CT at nucleotide 730-731 (730delCT), and also a two-base deletion of CA at position 982-983 (982delCA). Both of the deletion mutations lead to truncated proteins with an abnormal C-terminus, which would be expected to decrease the stability and/or activity of HMBS. Using the cleavage assays, we were able to definitively identify gene carriers in the family. This study adds a novel mutation to those that have been previously reported, and emphasizes that molecular analysis would be very useful not only for the identification of asymptomatic gene carriers in the family but also for the detection of ancestral founders in porphyria families.
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PMID:Two deletion mutations in the hydroxymethylbilane synthase gene in two unrelated Japanese patients with acute intermittent porphyria. 1094 60

Variegate porphyria is a rare disease caused by a deficiency of protoporphyrinogen oxidase. In most cases, the clinical findings are a combination of systemic symptoms similar to those occurring in acute intermittent porphyria and cutaneous lesions indistinguishable from those of porphyria cutanea tarda. We report on a 24-year-old woman with variegate porphyria who, after intake of lynestrenol, developed typical cutaneous lesions but no viscero-neurological symptoms. The diagnosis was based on the characteristic urinary coproporphyrin and faecal protoporphyrin excretion patterns, and the specific peak of plasma fluorescence at 626 nm in spectrofluorometry. Biochemical analysis revealed that most of the family members, though free of clinical symptoms, excrete porphyrin metabolites in urine and stool similar to variegate porphyria, accompanied by a significant decrease of porphobilinogen deaminase activity of a range which is ordinarily found in patients with acute intermittent porphyria only (approximately 50%). These data first led to the assumption of two separate and independently inherited genetic defects, similar to the dual porphyria of Chester. Molecular analysis, however, revealed only a missense mutation of the protoporphyrinogen oxidase gene, but not of the porphobilinogen deaminase gene. Thus, in the family presented, porphobilinogen deaminase deficiency is likely to be a phenomenon secondary to the genetic defect of protoporphyrinogen oxidase.
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PMID:Variegate porphyria with coexistent decrease in porphobilinogen deaminase activity. 1180 Jan 45

The porphyrias are a group of inherited metabolic disorders of heme biosynthesis which result from a partial deficiency in one of its seven specific enzymes, after its first and rate limiting enzyme, delta-aminolevulinic acid synthetase. They can be classified on the basis of their clinical manifestations into cutaneous, acute and mixed disorders. Acute intermittent porphyria (AIP) is the most common type of hepatic acute porphyrias, inherited as an autosomal dominant trait, caused by a defect in the gene which codifies for the heme enzyme porphobilinogen deaminase. Its prevalence in the Argentinean population is about 1:125,000. A partial deficiency in another enzyme, protoporphyrinogen oxidase, produces variegate porphyria (VP), the second acute porphyria most frequent in the Argentinean population (1:600,000). Here, we review all the mutations we have found in 46 AIP and 9 VP unrelated Argentinean patients. To screen for mutations in symptomatic patients, we have proposed a geneticresearch strategy.
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PMID:Acute porphyrias in the Argentinean population: a review. 1289 39

A 62-year-old man who had twice received laparotomies for abdominal pain of unknown origin was admitted to our hospital with acute abdominal pain. His family history of acute intermittent porphyria (AIP) suggested that it arose from acute porphyria. We treated the patient with 5% glucose solution by i.v. drip infusion and his abdominal pain improved rapidly. Diagnosis of AIP was established by the demonstration of reduced erythrocyte porphobilinogen deaminase (PBGD) activity and a point mutation (CAG --> CGG) in a splicing site in intron 10/exon 11 in the PBGD gene by DNA analysis. For screening of AIP carriers in his family, we measured erythrocyte PBGD activity. Four of his seven children were successfully diagnosed as AIP carriers. This is the ninth AIP family report, in which a mutation in the PBGD gene was revealed by DNA analysis.
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PMID:[A family of acute intermittent porphyria]. 1535 17


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