Acute intermittent porphyria: a single-base deletion and a nonsense mutation in the human hydroxymethylbilane synthase gene, predicting truncations of the enzyme polypeptide

An extremely rare combination of acute intermittent porphyria and Turner syndrome

A very rare case of acute intermittent porphyria (AIP) co-existing Turner syndrome (TS) is reported for the first time. A 32-year-old woman was diagnosed with AIP due to recurrent acute abdominal pain, red urine and pathogenic mutation of Hydroxymethyl synthetase (HMBS) gene. At the same time, TS was confirmed by Karyotype analysis results of 46,X,i(X)(q10), which accompanied by primary amenorrhea, elevated serum concentrations of follicle-stimulating hormone (FSH). Since the first attack of AIP, the patient has been increasingly depressed, and Psychiatry identified major depression. Duloxetine was chosen after careful deliberation, and the patient's mood stabilized. AIP had not recurred after half a year. Since sex hormones are the exacerbating factor of acute attack of AIP, sex hormone replacement therapy for TS was not administered. In conclusion, the conditions of AIP co-existing TS are complicate, and the treatment still needs to be improved by multiple disciplines in the follow-up.

Purple pigments: the pathophysiology of acute porphyric neuropathy

The porphyrias are inherited metabolic disorders arising from disturbance in the haem biosynthesis pathway. The neuropathy associated with acute intermittent porphyria (AIP) occurs due to mutation involving the enzyme porphobilinogen deaminase (PBGD) and is characterised by motor-predominant features. Definitive diagnosis often encompasses a combination of biochemical, enzyme analysis and genetic testing, with clinical neurophysiological findings of a predominantly motor axonal neuropathy. Symptomatic and supportive treatment are the mainstays during an acute attack. If administered early, intravenous haemin may prevent progression of neuropathy. While the pathophysiology of AIP neuropathy remains unclear, axonal dysfunction appears intrinsically linked to the effects of neural energy deficits acquired through haem deficiency coupled to the neurotoxic effects of porphyrin precursors. The present review will provide an overview of AIP neuropathy, including discussion of recent advances in understanding developed through neurophysiological approaches that have further delineated the pathophysiology of axonal degeneration.

Acute intermittent porphyria in Sweden. Molecular, functional and clinical consequences of some new mutations found in the porphobilinogen deaminase gene

Acute intermittent porphyria (AIP) is an autosomal dominant disorder caused by a partial deficit of porphobilinogen deaminase (PBGD), the third of eight enzymes in the haem biosynthetic pathway. The overt disease is characterized by neuropsychiatric symptoms that are often triggered by exogenous factors such as certain drugs, stress, and alcohol. The aim of this work has been to identify the underlying genetic defect in each AIP-affected family in order to provide early counselling to assist in the avoidance of precipitating factors. The prevalence of AIP in Sweden is in the order of 1:10 000. The major mutation in Sweden, W198X, is due to a founder effect in the northern part of the country. This mutation, together with a further 11 mutations, have been reported previously. The present communication encompasses the great majority of AIP kindreds in Sweden and includes a further 27 mutations within the PBGD gene. This includes 14 completely new mutations, as well as 11 known mutations detected for the first time in Sweden. The majority of the mutations are located in exons 10 and 12 with fewer in exon 7. The clinical and biochemical outcomes in some patients are described. We also use the three-dimensional structure of the porphobilinogen deaminase enzyme to predict the possible molecular and functional consequences of the new Swedish missense and nonsense mutations.

Porphobilmogen deaminase gene mutations in Brazilian acute intermittent porphyria patients

Acute intermittent porphyria (AIP) is an autosomal dominant disorder resulting from porphobilmogen deaminase (PBGD) deficiency. Seven unrelated Brazilian patients were investigated regarding PBGD gene mutations by polymerase chain reaction (PCR) and single strand conformation polymorphism (SSCP) analysis followed by direct DNA sequencing. The PBG gene screening disclosed abnormal SSCP patterns in exons 7, 9, 12, 13, and 15, as well as in introns 3 and 10. Direct DNA sequencing revealed the occurrence of three nonsense mutations (R149X, R225X, and R325X) in exons 9, 12, and 15, respectively, and one missense mutation G111R in exon 7. The G111R mutation was detected in two unrelated patients. Intragenic polymorphisms (3119G/T in intron 2, 3581G/A in intron 3, 7052A/G and 7064C/A in intron 10, and -65C/T in exon 1) were also observed. In addition, two silent mutations (V202V in exon 10 and A266A in exon 13) were found. The latter has not heretofore been reported. Thus, this study revealed the mutations involved in Brazilian symptomatic AIP patients, as well as the intragenic polymorphisms found in the patients.