Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.5.1.61 (porphobilinogen deaminase)
 637 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The long arm of chromosome 11 is of interest in schizophrenia research because of three independent reports of balanced 11q translocations cosegregating with schizophrenia and other major psychiatric illness in pedigrees. In addition, a number of candidate genes for psychosis are located in the translocated regions. These include the dopamine D2 receptor, porphobilinogen deaminase, which has shown an allelic association with schizophrenia, and neural cell adhesion molecule, a cell surface glycoprotein involved in neuronal cell-cell recognition during brain development. To search for a schizophrenia locus on chromosome 11q, we conducted linkage analyses in 12 multiplex pedigrees. Sixteen DNA markers, including the above three candidate genes, were used to screen the entire long arm of chromosome 11. None of these markers were supportive of linkage to schizophrenia regardless of whether the affected phenotype was defined narrowly or broadly, whether high or low penetrance was assumed. Both dominant and recessive models tested more than 130 centimorgans of chromosome 11q, and therefore, the reported translocation regions. The results provide no evidence for a susceptibility locus for schizophrenia on chromosome 11q in these pedigrees.
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PMID:A linkage study of chromosome 11q in schizophrenia. 843 42

We report the results of a collaborative linkage study using 12 polymorphic markers (9 loci) from the long arm of chromosome 11, and 24 families multiply affected with schizophrenia and other closely related disorders. This region is of interest because several families have been reported in which balanced translocations involving 11q apparently co-segregate with psychotic illness. In addition, the dopamine D2 receptor, porphobilinogen deaminase, and tyrosinase genes map within the region studied and may be aetiologically involved in schizophrenia. We have primarily analysed genotypic data by the LOD score method using a range of single gene models. In order to minimize error due to mis-specification of genetic parameters we have analysed data from markers at candidate gene loci by the non-parametric extended sib-pair method in addition to the LOD score method. Our results suggest that most of the region can be excluded from containing a gene of major effect in the aetiology of this disease.
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PMID:A linkage study of schizophrenia with DNA markers from the long arm of chromosome 11. 847 13

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

Acute intermittent porphyria (AIP) is the most common of the four forms of neuroporphyria. AIP mimics a variety of disorders and thus poses a diagnostic quagmire. Abdominal pain occurs in 90-95% of the attacks. Some patients develop psychiatric symptoms such as psychosis similar to schizophrenia. The diagnostic difficulty may lead to under-diagnosis of patients who present with strictly psychiatric symptoms. This assumption is supported by a high prevalence of AIP in psychiatric hospitals. Therefore, we encourage a high index of suspicion for AIP in psychiatric patients in order to prevent false psychiatric diagnosis. In addition we discuss psychotropic drugs that may exacerbate acute attacks in undiagnosed patients. We report a case in which the diagnosis of AIP was clouded by the presence of only psychiatric symptoms. The clue for diagnosis was an anamnestic detail of the use of a porphyrogenic drug prior to the admission. The diagnosis of AIP was supported by excess of alpha aminolevulinic acid (ALA) and porphobilinogen (PBG) in urine concomitantly with a decrease in porphobilinogen deaminase (PBGD) activity in erythrocytes. The diagnosis was further strengthened by the fact that the patient's father was identified as an AIP carrier. However, in the absence of typical organic symptoms of porphyria, one cannot definitely rule out the presence of schizophrenia in this patient in addition to AIR
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PMID:Acute intermittent porphyria: psychosis as the only clinical manifestation. 1691 Mar 86

Acute intermittent porphyria (AIP) is due to a deficiency of the third enzyme, the hydroxymethylbilane synthase, in heme biosynthesis. It manifests with occasional neuropsychiatric crises associated with overproduction of porphyrin precursors, aminolevulinic acid and porphobilinogen. The clinical criteria of an acute attack include the paroxysmal nature and various combinations of symptoms, such as abdominal pain, autonomic dysfunction, hyponatremia, muscle weakness, or mental symptoms, in the absence of other obvious causes. Intensive abdominal pain without peritoneal signs, acute peripheral neuropathy, and encephalopathy usually with seizures or psychosis are the key symptoms indicating possible acute porphyria. More than fivefold elevation of urinary porphobilinogen excretion together with typical symptoms of an acute attack is sufficient to start a treatment. Currently, the prognosis of the patients with AIP is good, but physicians should be aware of a potentially fatal outcome of the disease. Mutation screening and identification of type of acute porphyria can be done at the quiescent phase of the disease. The management of patients with AIP include following strategies: A, during an acute attack: 1) treatment with heme preparations, if an acute attack is severe or moderate; 2) symptomatic treatment of autonomic dysfunctions, polyneuropathy and encephalopathy; 3) exclusion of precipitating factors; and 4) adequate nutrition and fluid therapy. B, during remission: 1) exclusion of precipitating factors (education of patients and family doctors), 2) information about on-line drug lists, and 3) mutation screening for family members and education about precipitating factors in mutation-positive family members. C, management of patients with recurrent attacks: 1) evaluation of the lifestyle, 2) evaluation of hormonal therapy in women, 3) prophylactic heme therapy, and 4) liver transplantation in patients with severe recurrent attacks. D, follow-up of the AIP patients for long-term complications: chronic hypertension, chronic kidney insufficiency, chronic pain syndrome, and hepatocellular carcinoma.
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PMID:An update of clinical management of acute intermittent porphyria. 2636 3