Lavori Pubblicati

 

Un elenco degli ultimi lavori pubblicati dal GrIP o suoi membri

 

Brain perfusion defects by SPET/CT and neurostat semi-quantitative analysis in two patients with congenital erythropoietic porphyria

The assessment of noncoding variant of PPOX gene in variegate porphyria reveals post-transcriptional role of the 5′ untranslated exon 1.

Advances in understanding the pathogenesis of congenital erythropoietic porphyria.

X-chromosomal inactivation directly influences the phenotypic manifestation of X-linked protoporphyria.

Congenital erythropoietic porphyria linked to GATA1-R216W mutation: challenges for diagnosis.

A challenging diagnosis for potential fatal diseases: recommendations for diagnosing acute porphyrias

The acute porphyrias: a diagnostic and therapeutic challenge in internal and emergency medicine

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Brain perfusion defects by SPET/CT and neurostat semi-quantitative analysis in two patients with congenital erythropoietic porphyria

Vincenzo Frusciante, Cristina Ferrari, Manuela Totaro, Guido Valle, Claudio Carmine Guida, Filippo Aucella, Paola Caputo, Giuseppe Rubini

Hell J Nucl Med 2018; 21(1): 43-47

BACKGROUND: Congenital erythropoietic porphyria (CEP) is a rare autosomal recessively inherited disorder with chronic and relatively stable presentation. Till now brain blood flow derangements have been described only in acute hepatic porphyrias. We describe the first findings of brain perfusion defects, studied by single photon emission tomography/computed tomography (SPET/CT), in two patients affected by CEP, by using a semi-quantification anatomic-standardized voxel-based program compared with magnetic resonance imaging (MRI) results.
SUBJECTS AND METHODS: Two Pakistanis brothers were investigated for CEP confirmed by a genetic test. The disease was severe with: skin burning, mood depression and haemolytic anemia. Considering depression, patients underwent brain SPET/CT and MRI. Single photon emission tomography/CT images were processed by neurostat semi-quantitative software. Data obtained were compared to a normal database and z-score images were generated.
RESULTS: In both patients we found several perfusion defects evident in transaxial slices and in z-score images obtained by neurostat processing. Magnetic resonance imaging was negative in both patients. Biochemical mechanisms inducing localized brain hypoperfusion are uncertain. However, mismatch between SPET/CT data and MRI was probably due to absence of necrosis.
CONCLUSION: In our opinion, SPET/CT could have a key role in this setting of patients due to its high sensitivity and reliability in mild-to-moderate brain perfusion defects detection. Moreover, the quantitative analysis by using neurostat may allow to recognize even mild brain perfusion alterations, difficult to detect only visually.

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The assessment of noncoding variant of PPOX gene in variegate porphyria reveals post-transcriptional role of the 5′ untranslated exon 1.

Fiorentino V, Brancaleoni V, Granata F, Graziadei G, Di Pierro E.

Blood Cells Mol Dis. 2016 Oct;61:48-53

The PPOX gene encodes for the protoporphyrinogen oxidase, which is involved in heme production. The partial deficiency of protoporphyrinogen oxidase causes variegate porphyria. The tissue-specific regulation of other heme biosynthetic enzymes is extensively studied, but the information concerning transcriptional and post-transcriptional regulation of PPOX gene expression is scarcely available. In this study, we characterized functions of three variants identified in the regulatory regions of the PPOX gene, which show a novel role for the 5′ untranslated exon 1. Using luciferase assays and RNA analysis, we demonstrated that only c.1-883G>C promoter variant causes a significant loss in the transcriptional activity of PPOX gene whereas c.1-413G>T 5′ UTR variant inhibits translation of PPOX mRNA and c.1-176G>A splicing variant causes 4bp deletion in 5′ UTR of PPOX mRNA variant 2. These observations indicate that the regulation of PPOX gene expression can also occur through a post-transcriptional modulation of the amount of gene product and that this modulation can be mediated by 5′ untranslated exon 1. Moreover this study confirms that these regulatory regions represent an important molecular target for the pathogenesis of variegate porphyria.

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Advances in understanding the pathogenesis of congenital erythropoietic porphyria.

Di Pierro E, Brancaleoni V, Granata F.

Br J Haematol. 2016 May;173(3):365-79.

Congenital erythropoietic porphyria (CEP) is a rare genetic disease resulting from the remarkable deficient activity of uroporphyrinogen III synthase, the fourth enzyme of the haem biosynthetic pathway. This enzyme defect results in overproduction of the non-physiological and pathogenic porphyrin isomers, uroporphyrin I and coproporphyrin I. The predominant clinical characteristics of CEP include bullous cutaneous photosensitivity to visible light from early infancy, progressive photomutilation and chronic haemolytic anaemia. The severity of clinical manifestations is markedly heterogeneous among patients; and interdependence between disease severity and porphyrin amount in the tissues has been pointed out. A more pronounced endogenous production of porphyrins concomitant to activation of ALAS2, the first and rate-limiting of the haem synthesis enzymes in erythroid cells, has also been reported. CEP is inherited as autosomal recessive or X-linked trait due to mutations in UROS or GATA1 genes; however an involvement of other causative or modifier genes cannot be ruled out.

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X-chromosomal inactivation directly influences the phenotypic manifestation of X-linked protoporphyria.

Brancaleoni V, Balwani M, Granata F, Graziadei G, Missineo P, Fiorentino V, Fustinoni S, Cappellini MD, Naik H, Desnick RJ, Di Pierro E.

Clin Genet. 2016 Jan;89(1):20-6.

X-linked protoporphyria (XLP), a rare erythropoietic porphyria, results from terminal exon gain-of-function mutations in the ALAS2 gene causing increased ALAS2 activity and markedly increased erythrocyte protoporphyrin levels. Patients present with severe cutaneous photosensitivity and may develop liver dysfunction. XLP was originally reported as X-linked dominant with 100% penetrance in males and females. We characterized 11 heterozygous females from six unrelated XLP families and show markedly varying phenotypic and biochemical heterogeneity, reflecting the degree of X-chromosomal inactivation of the mutant gene. ALAS2 sequencing identified the specific mutation and confirmed heterozygosity among the females. Clinical history, plasma and erythrocyte protoporphyrin levels were determined. Methylation assays of the androgen receptor and zinc-finger MYM type 3 short tandem repeat polymorphisms estimated each heterozygotes X-chromosomal inactivation pattern. Heterozygotes with equal or increased skewing, favoring expression of the wild-type allele had no clinical symptoms and only slightly increased erythrocyte protoporphyrin concentrations and/or frequency of protoporphyrin-containing peripheral blood fluorocytes. When the wild-type allele was preferentially inactivated, heterozygous females manifested the disease phenotype and had both higher erythrocyte protoporphyrin levels and circulating fluorocytes. These findings confirm that the previous dominant classification of XLP is inappropriate and genetically misleading, as the disorder is more appropriately designated XLP.

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Congenital erythropoietic porphyria linked to GATA1-R216W mutation: challenges for diagnosis.

Di Pierro E, Russo R, Karakas Z, Brancaleoni V, Gambale A, Kurt I, Winter SS, Granata F, Czuchlewski DR, Langella C, Iolascon A, Cappellini MD.

Eur J Haematol. 2015 Jun;94(6):491-7.

Congenital erythropoietic porphyria (CEP) is a rare genetic disease that is characterized by a severe cutaneous photosensitivity causing unrecoverable deformities, chronic hemolytic anemia requiring blood transfusion program, and by fatal systemic complications. A correct and early diagnosis is required to develop a management plan that is appropriate to the patient’s needs. Recently only one case of X-linked CEP had been reported, describing the trans-acting GATA1-R216W mutation. Here, we have characterized two novel X-linked CEP patients, both with misleading hematological phenotypes that include dyserythropoietic anemia, thrombocytopenia, and hereditary persistence of fetal hemoglobin. We compare the previously reported case to ours and propose a diagnostic paradigm for this variant of CEP. Finally, a correlation between phenotype variability and the presence of modifier mutations in loci related to disease-causing gene is described.

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A challenging diagnosis for potential fatal diseases: recommendations for diagnosing acute porphyrias.

Ventura P, Cappellini MD, Biolcati G, Guida CC, Rocchi E; Gruppo Italiano Porfiria (GrIP).

Eur J Intern Med. 2014 Jul;25(6):497-505.

Acute porphyrias are a heterogeneous group of metabolic disorders resulting from a variable catalytic defect of four enzymes out of the eight involved in the haem biosynthesis pathway; they are rare and mostly inherited diseases, but in some circumstances, the metabolic disturbance may be acquired. Many different environmental factors or pathological conditions (such as drugs, calorie restriction, hormones, infections, or alcohol abuse) often play a key role in triggering the clinical exacerbation (acute porphyric attack) of these diseases that may often mimic many other more common acute medical and neuropsychiatric conditions and whose delayed diagnosis and treatment may be fatal. In order to obtain an accurate diagnosis of acute porphyria, the knowledge and the use of appropriate diagnostic tools are mandatory, even in order to provide as soon as possible the more effective treatment and to prevent the use of potentially unsafe drugs, which can severely precipitate these diseases, especially in the presence of life-threatening symptoms. In this paper, we provide some recommendations for the diagnostic steps of acute porphyrias by reviewing literature and referring to clinical experience of the board members of the Gruppo Italiano Porfiria (GrIP).

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The acute porphyrias: a diagnostic and therapeutic challenge in internal and emergency medicine.

Ventura P, Cappellini MD, Rocchi E.

Intern Emerg Med. 2009 Aug;4(4):297-308.

The porphyrias are a heterogeneous group of metabolic diseases resulting from a variable catalytic defect of one of the eight enzymes involved in the heme biosynthesis pathway; they are mostly inherited diseases, but in some circumstances the metabolic disturbance may be acquired. The specific patterns of tissue overproduction (and hence accumulation and excretion) of toxic heme precursors, associated with each enzymatic deficiency, are responsible for the characteristic biochemical and clinical features of each of these diseases. Moreover, even in the presence of a specific inherited enzymatic defect, many different environmental factors (such as drugs, calorie restriction, hormones, sunlight exposition, infections, etc.) often play a key role in triggering the clinical expression of the various forms of porphyrias. The porphyrias are often misdiagnosed diseases, due their multiform clinical manifestations, able to mimic many other more common diseases. For this reason, many different specialists, such as surgeons, psychiatrists, gastroenterologists, neurologists, emergency physicians and dermatologists may be variably involved in the diagnostic process, especially for the forms presenting with acute and life-threatening clinical features. According to the clinical features, the porphyrias can be classified into neuropsychiatric (characterized by neurovisceral crises involving autonomic and central nervous system but also the liver and the kidney with possible consequences in terms of neurological, psychic, cardiac, respiratory, liver and kidney functions), dermatological (mostly presenting with cutaneous lesions due to photosensitivity), and mixed forms. From a strictly clinical point of view, porphyrias presenting with neurovisceral attacks are also referred as acute porphyrias: they are the object of the present review. An accurate diagnosis of acute porphyria requires knowledge and the use of correct diagnostic tools, and it is mandatory to provide a more appropriate therapeutic approach and prevent the use of potentially unsafe drugs, able to severely precipitate these diseases, especially in the presence of life-threatening symptoms. To date, availability of a relatively stable haem preparation (haem arginate) has significantly improved the treatment outcome of acute porphyric attacks, so the knowledge about the diagnosis and the management of these diseases may be relevant for physicians working in internal medicine, neurology and emergency units.