Porfiria hepato eritropoyética asociada a diabetes mellitus tipo 1: a propósito de un caso clínico / A clinical case of hepato-erythropoietic porphyria associated with type 1 diabetes mellitus / Relato de caso de porfiria hepato-eritropoiética associada a diabetes mellitus tipo 1

Las porfirias son un grupo complejo y heterogéneo de defectos en la vía de la síntesis del hemo. La porfiria hepato eritropoyética es un subtipo muy poco frecuente y de presentación en la infancia, con compromiso cutáneo predominante. Describimos el caso clínico de una paciente de 5 años, que se presenta con lesiones cutáneas e hipertricosis, se confirma el diagnóstico por elevación de uroporfirinas en orina y secuenciación del gen UROD.

Porphyria is a complex and heterogeneous group of heme synthesis disorder. Hepato-erythropoietic porphyria is a very rare subtype that onsets in childhood, and shows predominant skin involvement. We describe the clinical case of a 5-year-old patient who showed skin lesions and hypertrichosis and whose diagnosis was confirmed due to increased uroporphyrins in urine and UROD gene sequencing

A porfiria é um grupo complexo e heterogêneo de distúrbios da síntese do grupo heme. A porfiria hepato-eritropoiética é um subtipo muito raro que se inicia na infância e mostra envolvimento predominante da pele. Descrevemos o caso clínico de uma paciente de 5 anos que apresentou lesões cutâneas e hipertricose e cujo diagnóstico foi confirmado por aumento de uroporfirinas na urina e sequenciamento do gene UROD.

Porphyria cutanea tarda and hepatoerythropoietic porphyria: Identification of 19 novel uroporphyrinogen III decarboxylase mutations.

Porphyria Cutanea Tarda (PCT) is a cutaneous porphyria that results from the hepatic inhibition of the heme biosynthetic enzyme uroporphyrinogen decarboxylase (UROD), and can occur either in the absence or presence of an inherited heterozygous UROD mutation (PCT subtypes 1 and 2, respectively). A heterozygous UROD mutation causes half-normal levels of UROD activity systemically, which is a susceptibility factor but is not sufficient alone to cause type 2 PCT. In both Types 1 and 2 PCT, the cutaneous manifestations are precipitated by additional factors that lead to generation of an inhibitor that more profoundly reduces hepatic UROD activity. PCT is an iron-related disorder, and many of its known susceptibility factors, which include infections (e.g. hepatitis C virus, HIV), high alcohol consumption, smoking, estrogens, and genetic traits (e.g. hemochromatosis mutations) can increase hepatic iron accumulation. Hepatoerythropoietic Porphyria (HEP) is a rare autosomal recessive disease that results from homozygosity or compound heterozygosity for UROD mutations and often causes infantile or childhood onset of both erythropoietic and cutaneous manifestations. During the 11-year period from 01/01/2007 through 12/31/2017, the Mount Sinai Porphyrias Diagnostic Laboratory provided molecular diagnostic testing for 387 unrelated patients with PCT and four unrelated patients with HEP. Of the 387 unrelated individuals tested for Type 2 PCT, 79 (20%) were heterozygous for UROD mutations. Among 26 family members of mutation-positive PCT patients, eight (31%) had the respective family mutation. Additionally, of the four unrelated HEP patients referred for UROD mutation analyses, all had homozygosity or compound heterozygosity for UROD mutations, and all eight asymptomatic family members were heterozygotes for UROD mutations. Of the UROD mutations identified, 19 were novel, including nine missense, two nonsense, one consensus splice-site, and seven insertions and deletions. These results expand the molecular heterogeneity of PCT and HEP by adding a total of 19 novel UROD mutations. Moreover, the results document the usefulness of molecular testing to confirm a genetic susceptibility trait in Type 2 PCT, confirm a diagnosis in HEP, and identify heterozygous family members.

Hepatoerythropoietic Porphyria Caused by a Novel Homoallelic Mutation in Uroporphyrinogen Decarboxylase Gene in Egyptian Patients.

Porphyrias are metabolic disorders resulting from mutations in haem biosynthetic pathway genes. Hepatoerythropoietic porphyria (HEP) is a rare type of porphyria caused by the deficiency of the fifth enzyme (uroporphyrinogen decarboxylase, UROD) in this pathway. The defect in the enzymatic activity is due to biallelic mutations in the UROD gene. Currently, 109 UROD mutations are known. The human disease has an early onset, manifesting in infancy or early childhood with red urine, skin photosensitivity in sun-exposed areas, and hypertrichosis. Similar defects and links to photosensitivity and hepatopathy exist in several animal models, including zebrafish and mice. In the present study, we report a new mutation in the UROD gene in Egyptian patients with HEP. We show that the homozygous c.T163A missense mutation leads to a substitution of a conserved phenylalanine (amino acid 55) for isoleucine in the enzyme active site, causing a dramatic decrease in the enzyme activity (19 % of activity of wild-type enzyme). Inspection of the UROD crystal structure shows that Phe-55 contacts the substrate and is located in the loop that connects helices 2 and 3. Phe-55 is strictly conserved in both prokaryotic and eukaryotic UROD. The F55I substitution likely interferes with the enzyme-substrate interaction.

Hepatoerythropoietic porphyria due to a novel mutation in the uroporphyrinogen decarboxylase gene.

BACKGROUND: Hepatoerythropoietic porphyria (HEP) is a rare form of porphyria that results from a deficiency of uroporphyrinogen decarboxylase (UROD). The disease is caused by homoallelism or heteroallelism for mutations in the UROD gene. OBJECTIVE: To study a 19-year-old woman from Equatorial Guinea, one of the few cases of HEP of African descent and to characterize a new mutation causing HEP. METHODS: Excretion of porphyrins and residual UROD activity in erythrocytes were measured and compared with those of other patients with HEP. The UROD gene of the proband was sequenced and a new mutation identified. The recombinant UROD protein was purified and assayed for enzymatic activity. The change of amino acid mapped to the UROD protein and the functional consequences were predicted. RESULTS: The patient presented a novel homozygous G170D missense mutation. Porphyrin excretion showed an atypical pattern in stool with a high pentaporphyrin III to isocoproporphyrin ratio. Erythrocyte UROD activity was 42% of normal and higher than the activity found in patients with HEP with a G281E mutation. The recombinant UROD protein showed a relative activity of 17% and 60% of wild-type to uroporphyrinogen I and III respectively. Molecular modelling showed that glycine 170 is located on the dimer interface of UROD, in a loop containing residues 167-172 that are critical for optimal enzymatic activity and that the carboxyl side chain from aspartic acid is predicted to cause negative interactions between the protein and the substrate. CONCLUSIONS: The results emphasize the complex relationship between the genetic defects and the biochemical phenotype in homozygous porphyria.

Hepatoerythropoietic porphyria misdiagnosed as child abuse: cutaneous, arthritic, and hematologic manifestations in siblings with a novel UROD mutation.

BACKGROUND: Hepatoerythropoietic porphyria (HEP) is a rare autosomal recessive disorder resulting from the markedly deficient, but not absent, activity of the heme biosynthetic enzyme uroporphyrinogen decarboxylase (UROD). The disorder typically manifests during infancy or early childhood with extreme photosensitivity, skin fragility in sun-exposed areas, hypertrichosis, erythrodontia, and pink urine. OBSERVATIONS: Three siblings, offspring of parents of Puerto Rican and Dominican descent, had with excessive scarring on the face and dorsal aspect of the forearms, which initially led to the erroneous suspicion of child abuse. Although these lesions were photodistributed, overt photosensitivity had not been observed, with the exception of a single episode of blistering and onycholysis after intense sun exposure in 1 affected child. Mild facial hypertrichosis, chronic anemia, polyarticular arthritis, and developmental delay represented additional findings. Biochemical studies of urine, plasma, and erythrocyte porphyrins from the affected siblings established the diagnosis of HEP. Sequencing of the UROD gene revealed compound heterozygosity for a novel missense mutation, V166A, and a complex deletion/insertion, 645del1053ins10. CONCLUSIONS: Our report expands the phenotypic and genotypic spectrum of HEP, highlighting mild cutaneous presentations that can occur without obvious photosensitivity and masquerade as child abuse.

GoGene: gene annotation in the fast lane.

High-throughput screens such as microarrays and RNAi screens produce huge amounts of data. They typically result in hundreds of genes, which are often further explored and clustered via enriched GeneOntology terms. The strength of such analyses is that they build on high-quality manual annotations provided with the GeneOntology. However, the weakness is that annotations are restricted to process, function and location and that they do not cover all known genes in model organisms. GoGene addresses this weakness by complementing high-quality manual annotation with high-throughput text mining extracting co-occurrences of genes and ontology terms from literature. GoGene contains over 4,000,000 associations between genes and gene-related terms for 10 model organisms extracted from more than 18,000,000 PubMed entries. It does not cover only process, function and location of genes, but also biomedical categories such as diseases, compounds, techniques and mutations. By bringing it all together, GoGene provides the most recent and most complete facts about genes and can rank them according to novelty and importance. GoGene accepts keywords, gene lists, gene sequences and protein sequences as input and supports search for genes in PubMed, EntrezGene and via BLAST. Since all associations of genes to terms are supported by evidence in the literature, the results are transparent and can be verified by the user. GoGene is available at http://gopubmed.org/gogene.

The very first description of a patient with hepatoerythropoietic porphyria in Argentina. Biochemical and molecular studies.

Hepatoerythropoietic Porphyria (HEP) is the rare homozygous form of Porphyria Cutanea Tarda (PCT). It is characterized clinically by the early onset of severe skin manifestations which can be confused with Congenital Erythropoietic Porphyria (CEP) or with PCT when the symptoms are mild. We describe the case of a 14 year-old child with skin manifestations similar to those observed in PCT. The biochemical assays ruled out a CEP as well as they suggested the development of a HEP. Although his symptoms were not severe enough to be HEP, the enzymatic activity was dramatically reduced to a 5% of normal values and the molecular analysis revealed the presence of two already known different mutations on the patient's URO-D gene, c.703 C>T and IVS9-1. Each parent carry one of the mutations, but they were absent in the brother. This is the first Argentinean HEP case ever described which appeared in a compound heterozygous form and less residual URO-D activity but associated to a mild phenotype.

Erythropoietic porphyrias: animal models and update in gene-based therapies.

The inherited porphyrias are inborn errors of haem biosynthesis, each resulting from the deficient activity of a specific enzyme of the haem biosynthetic pathway. Porphyrias are divided into erythropoietic and hepatic according to the predominant porphyrin-accumulating tissue. Three different erythropoietic porphyrias (EP) have been described: erythropoietic protoporphyria (EPP, MIM 177000) the most frequent, congenital erythropoietic porphyria (CEP, MIM 263700), and the very rare hepatoerythropoietic porphyria (HEP, MIM 176100). Bone marrow transplantation is considered as the only curative treatment for severe cases of erythropoietic porphyria (especially CEP), if donors are available. Some EPP patients who undergo liver failure may require hepatic transplantation. Murine models of EPP and CEP have been developed and mimic most of the human disease features. These models allow a better understanding of the pathophysiological mechanisms involved in EP as well as the development of new therapeutic strategies. The restoration of deficient enzymatic activity in the bone marrow compartment following gene therapy has been extensively studied. Murine oncoretroviral, and recently, lentiviral vectors have been successfully used to transduce hematopoietic stem cells, allowing full metabolic and phenotypic correction of both EPP and CEP mice. In CEP, a selective survival advantage of corrected cells was demonstrated in mice, reinforcing the arguments for a gene therapy approach in the human disease. These successful results form the basis for gene therapy clinical trials in severe forms of erythropoietic porphyrias.

Two novel uroporphyrinogen decarboxylase (URO-D) mutations causing hepatoerythropoietic porphyria (HEP).

Hepatoerythropoietic porphyria (HEP) is a rare form of porphyria in humans. The disorder is caused by homozygosity or compound heterozygosity for mutations of the uroporphyrinogen decarboxylase (URO-D) gene. Subnormal URO-D activity results in accumulation of uroporphyrin in the liver, which ultimately mediates the photosensitivity that clinically characterizes HEP. Two previously undescribed URO-D mutations found in a 2-year-old Caucasian boy with HEP, a maternal nonsense mutation (Gln71Stop), and a paternal missense mutation (Gly168Arg) are reported here. Recombinant Gly168Arg URO-D retained 65% of wild-type URO-D activity and studies in Epstein-Barr Virus (EBV)-transformed lymphoblasts indicated that protein levels are reduced, suggesting that the mutant protein might be subjected to accelerated turnover. The crystal structure of Gly168Arg was determined both as the apo-enzyme and with the reaction product bound. These studies revealed little distortion of the active site, but a loop containing residues 167-172 was displaced, possibly indicating small changes in the catalytic geometry or in substrate binding or increased accessibility to a cellular proteolytic pathway. A second pregnancy occurred in this family, and in utero genotyping revealed a fetus heterozygous for the maternal nonsense mutation (URO-D genotype WT/Gln71Stop). A healthy infant was born with no clinical evidence of porphyria.

Porfirias poco frecuentes: Casos detectados en la población argentina / Non frequent porphyrias in the argentinean population

Las porfirias son consecuencia de fallas en el metabolismo del hemo. Se clasifican según el tipo de sintomatología clínica prevalente o el órgano donde se expresa preferencialmente la falla metabólica. En general la deficiencia enzimática está asociada a mutaciones en los genes que codifican para cada una de las enzimas. Están descritos 7 tipos de porfiria diferentes. Se transmiten por carácter autosómico dominante a excepción de la PCE, la PHE y la NPA que son recesivas. Sin embargo, están reportadas variantes homocigotas para el resto de las porfirias de pronóstico y evolución mucho más grave que la forma heterocigota. La descripción de estos casos poco frecuentes, sus tratamientos y evolución, facilitarían tanto el diagnóstico diferencial de la porfiria como el conocimiento de las posibilidades terapéuticas en cada caso. Asimismo para las porfirias heterocigotas con manifestación infantil, su identificación temprana y tratamiento aseguraría una mejor evolución minimizando los riesgos asociados. Se han diagnosticado 5 casos de porfirias agudas en niñas: 2 de PAI, 2 de PV y 1 de CPH. Entre las porfirias cutáneas se presentan 25 casos de PCT infantil, el primer caso de PHE en Argentina, 4 casos de PCE infantil y 1 en un adulto y 2 casos de PPE con compromiso hepatobiliar.

The Porphyrias are a group of diseases resulting from partial deficiencies in one of the heme biosynthetic enzymes. These disorders can be classified on the basis of their clinical manifestations or according the organ where the metabolic deficiency is mainly expressed. In general this enzyme deficiency is associated with mutations in the genes which codify each enzyme. There are 7 types of Porphyrias. They are autosomal dominant disorders with the exception of PCE, PHE and NPA which are recessive. However, some rare and severe cases with recessive inheritance have also been reported. The description of these infrequent cases and their treatments and evolution would make easier the differential diagnosis of Porphyrias as well as the therapeutic possibilities to be applied in each case. Moreover, it is very important the early identification and treatment of infantile heterozygous porphyrias to avoid the risks of associatedd complications. In the CIPYP we have diagnosed 5 cases of infantil Acute Porphyrias: 2 PAI, 2 PV and 1 CPH. In the group of Cutaneous Porphyrias we present 25 cases of infantil PCT, the first case of PHE in Argentina, 4 cases of infantil PCE and 1 adult PCE and 2 cases of PPE with hepatic failure.

Modern diagnosis and management of the porphyrias.

Recent advances in the molecular understanding of the porphyrias now offer specific diagnosis and precise definition of the types of genetic mutations involved in the disease. Molecular diagnostic testing is powerful and very useful in kindred evaluation and genetic counselling when a disease-responsible mutation has been identified in the family. It is also the only way to properly screen asymptomatic gene carriers, facilitating correct treatment and appropriate genetic counselling of family members at risk. However, it should be noted that DNA-based testing is for the diagnosis of the gene carrier status, but not for the diagnosis of clinical syndrome or severity of the disease, e.g. an acute attack. For the diagnosis of clinically expressed porphyrias, a logical stepwise approach including the analysis of porphyrins and their precursors should not be underestimated, as it is still very useful, and is often the best from the cost-effective point of view.

1599: first iconographic description of hepatoerythropoietic porphyria.

The author's aim was to contribute information to the history of porphyrias through the analysis of a 16th century portrait. The subject drawn by physician Aldrovandi is a 20-year-old girl showing remarkable facial hypertrichosis, while her body is described as hairless. After a brief excursus through the history of porphyrias, the author revisited a previous diagnosis of hypertrichosis lanuginosa with the aid of current clinical findings. Accurate research of the drawings by the 16th century physician together with the study of our case's family history have supplied information on the young woman affected by hirsutism, such as the absence of hair on her body surface. Careful observation together with updated knowledge resulted in a diagnosis of hepatoerythropoietic porphyria; a disease characterized by severe facial hypertrichosis, a hairless body, and very early onset and heredity.

Enfermedad hepática en la protoporfiria eritropoyética / Liver disease in erythropoietic protoporphyria

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Porfirias cutáneas / Cutaneous porphyrias

Las porfirias son un grupo heterogéneo de trastornos causados por un déficit parcial genético o adquirido de las enzimas que regulan la síntesis del grupo hemo. De acuerdo con la presencia o ausencia de fotosensibilidad cutánea, estas enfermedades pueden clasificarse en porfirias cutáneas y no cutáneas. Existen 5 tipos principales de porfirias cutáneas: la porfiria cutánea tarda (PCT); la porfiria variegata (PV); la coproporfiria hereditaria (CPH); la protoporfiria eritropoyética (PPE); y la porfiria eritropoyética congénita (PEC). La PV, CPH, PPE y la PCT tipo II son trastornos autonómicos dominantes con baja penetrancia. Las formas autosómicas recesivas (CEP y porfiria hepatoeritrocitaria, PHE) son trastornos de inicio precoz y muy raros. Las lesiones cutáneas en la PCT, la porfiria más frecuente, PV, CPH y PEC son similares: fragilidad mecánica, ampollas subepidérmicas, hipertricosis y pigmentación. PPE se caracteriza por una fotosensibilidad aguda y sin estas lesiones. Los ataques agudos de porfiria pueden ocurrir en la PV y CPH pero no en las otras porfirias cutáneas. La afectación hepática es una complicación infrecuente pero potencialmente fatal de la PPE. La PCT se asocia frecuentemente con enfermedad hepática crónica que a menudo es causada por el alcohol y suele ser leve. El diagnóstico clínico debe siempre confirmarse mediante análisis bioquimicos de porfirinas en orina, heces y sangre. La PCT puede ser tratada mediante sangrías repetidas para depleccionar los depósitos de hierro o mediante cloroquina a bajas dosis. El tratamiento de los otros tipos de porfiria cutánea es principalmente sintomático

The porphyrias are a heterogeneous group of disorders caused by genetically determined or acquired partial deficiencies of enzymes regulating heme biosynthesis. According to the presence or absence of cutaneous photosensitivity, these diseases can be classified into cutaneous and noncutaneous porphyrias. There are five main types of cutaneous porphyrias : porphyria cutanea tarda (PCT); variegate porphyria (VP); hereditary coproporphyria (He); erythropoietic protoporphyria (EPP); and congenital erythropoietic porphyria (CEP) Vp, HC, EPp, and one form of PCT (type II) are autosomal dominant conditions with low elinical penetrance. The autosomal recessive prophyrias (CEP and Hepatoerythropoietic porphyria, HEP) are rare disorders with early onset. The skin lesions in PCT (the commonest cutaneous porphyria), VP, HC, and CEP are similar: mechanical fragility, subepidermal bullae, hypertrichosis, and pigmentation. EPP is characterized by acute photosensitivity without these lesions. Acute attacks of porphyria may occur in VP and HC but not in other cutaneous porphyrias. Liver disease is an uncommon, potentially fatal, complication of EPP PCT is commonly associated with chronic liver disease, is often caused by alcohol and usually mild. The clinical diagnosis should always be confirmed by biochemical porphyrin analyses in urine, stool and blood. PCT can be treated by repeated venesection to deplete iron stores or with low-dose chloroquine. Treatment of the other cutaneous porphyrias is largely symptomatic

Erythrocytes-the 'house elves' of photodynamic therapy.

Photodynamic therapy (PDT) and fluorescence diagnosis (FD) are being developed for a number of clinical applications. Since fluorophores and photosensitising drugs are usually given systemically their effect on blood elements are of significant importance. Photodynamic effects on erythrocytes occur naturally in patients with erythropoietic protoporphyria (EPP). Exposure to small fluences, as obtained by the erythrocytes when they pass capillaries in the skin, leads to transfer of the photosensitiser protoporphyrin IX (PP IX), from EPP erythrocytes to endothelial cells. Thus, the erythrocytes are partly protected while the endothelial cells suffer photodamage. During photodynamic therapy in vivo erythrocytes are regularly photosensitised. This side effect is partly intended but mostly unwanted, and a summary of this topic is given. Furthermore, the effect of UV-A on erythrocytes that is accompanied with the formation of bilirubin is reviewed. Erythrocytes serve as convenient model cells for experimental research. Such use of erythrocytes to screen new photosensitisers may be of limited value. A combination of photohaemolysis and haemoglobin oxygenation may become the basis for an assay for in vitro phototoxicity. Erythrocytes from birds are good model cells for exploration of physiological and molecular mechanisms involved in PDT. A potential mechanism of PDT induced behaviour resembling apoptosis in erythrocytes is provided.PDT for sterilisation of erythrocyte concentrates has a potential for medical use. Photodynamic effects on the erythrocytes themselves should be avoided. This is realised by choosing a virus-selective photosensitiser, low fluences and treatment of the concentrates with agents like dipyridamole and antioxidants. Future aspects of applications of photosensitisation of red blood cells are discussed.

Hepatoerythropoietic porphyria: a missense mutation in the UROD gene is associated with mild disease and an unusual porphyrin excretion pattern.

Hepatoerythropoietic porphyria (HEP) is an uncommon inherited cutaneous porphyria, related to porphyria cutanea tarda, that results from severe uroporphyrinogen decarboxylase (UROD) deficiency. It is characterized clinically by the onset in early childhood of severe lesions on sun-exposed skin. We describe a man aged 38 years with an unusually mild form of the disease that started in his early teens. Our data confirm that homozygosity for the F46L mutation in the UROD gene causes a mild form of HEP and show that this genotype may be associated with a unique urinary porphyrin excretion pattern in which pentacarboxylic porphyrin predominates.