[Congenital erythropoietic porphyria : An update]. / Kongenitale erythropoetische Porphyrie : Ein Update.

BACKGROUND: Congenital erythropoetic porphria is a very rare type of autosomal recessive nonacute porphyria. Homozygous or compound heterozygous mutations in the uroporphyrinogen III consynthase gene cause a marked enzymatic deficiency of uroporphyrinogen III consynthase, the fourth enzyme along the heme biosynthetic pathway. CLINICAL PRESENTATION: Clinically, affected patients are characterized by a moderate to severe photosensitivity. Starting early in infancy, they develop blisters, erosions, and exulcerations in sun-exposed areas of the body, often resulting in scar formation and mutilation. Besides the cutaneous changes, hemolytic anemia, transfusion-dependent pancytopenia, hepatosplenomegaly and liver cirrhosis can occur. Due to increased susceptibility for infections and because of the hematological and hepatic complications, affected individuals have a decreased life expectancy, rarely exceeding 40 years of age. TREATMENT: Currently, no causal treatment is available for the disorder. Therefore, the most important therapeutic modality is strict avoidance of sunlight, preferably by inversion of the day-night rhythm, or at least consequent photoprotection with adequate clothing. In severe cases, bone marrow or stem cell transplantation should be considered.

Porphyrias in Norway.

BACKGROUND: Porphyria is an umbrella term for a group of largely hereditary diseases that are due to defective haem synthesis. The diseases have a varied and partly overlapping range of symptoms and presentations. The commonest forms of porphyria are porphyria cutanea tarda, acute intermittent porphyria and erythropoietic protoporphyria. The purpose of this study is to provide an overview of the prevalence and pathological manifestations of porphyrias in Norway. MATERIAL AND METHOD: Information on all patients registered with the Norwegian Porphyria Centre (NAPOS) up to 2012 was used to estimate the prevalence and incidence of porphyrias in Norway. Figures on symptoms, precipitating factors and follow-up routines were obtained from the Norwegian Porphyria Registry, which includes 70% of Norwegians registered with NAPOS as having porphyria. RESULTS: The prevalence of porphyria cutanea tarda was approximately 10 : 100,000 and that of acute intermittent porphyria approximately 4 : 100,000. The total incidence of all porphyrias was approximately 0.5-1 : 100,000 per year. Diagnostic delay, i.e. the time passing between the onset of symptoms and diagnosis, varied from 1-17 years depending on the type of porphyria. There was wide variation in the frequency with which patients with the various types of porphyria went for medical check-ups. INTERPRETATION: The prevalence of acute intermittent porphyria and porphyria cutanea tarda appears to be higher in Norway than in most other countries. Data from the Norwegian Porphyria Registry makes it possible to demonstrate differences in treatment and follow-up of porphyria patients and may be used to initiate necessary measures.

Novedades en las porfirias eritropoyéticas / New Developments in Erythropoietic Porphyrias

En los últimos años se han producido importantes avances en la genética de las porfirias y, concretamente, en las porfirias eritropoyéticas -protoporfiria eritropoyética (PPE) y porfiria eritropoyética congénita (PEC)-, que han dado lugar a una nueva concepción de las mismas como enfermedades no monogénicas. Se han identificado mutaciones en nuevos genes como responsables o modificadores de la gravedad de la porfiria, permitiendo esclarecer las discrepancias geno-fenotípicas observadas entre pacientes portadores de las mismas mutaciones, así como identificar el defecto genético responsable de algunos casos de porfiria en los que los estudios moleculares del gen uroporfirinógeno sintetasa (UROS) en la PEC o del gen ferroquelatasa (FECH) en la PPE no identificaban ninguna mutación. La mejor caracterización y conocimiento de la genética de estas enfermedades permitirá establecer cuadros geno-fenotípicos concretos y realizar una clasificación molecular con implicaciones prácticas y pronósticas (AU)

In recent years, important advances have been made in our understanding of the genetics of porphyrias, particularly with respect to erythropoietic protoporphyria (EPP) and congenital erythropoietic porphyria (CEP), 2 forms of erythropoietic porphyria no longer considered to be monogenic. The identification of mutations in genes not previously associated with these disorders as causative factors or modulators of severity has helped to explain the presence of genotypic and phenotypic differences between patients carrying the same mutations. These advances have also led to the identification of causative genetic defects in patients who, based on molecular studies, had no mutations in the uroporphyrinogen III synthase gene UROS (in CEP) or in the ferrochelatase gene FECH (in EPP). Better understanding and characterization of the genetics of porphyrias will allow us to determine genotypic and phenotypic correlations and improve the molecular classification of these diseases, which will have both practical and prognostic implications (AU)

[Erythropoietic porphyrias]. / Erytropoieettiset porfyriat.

Erythropoietic, i.e., myelogenous porphyrias include erythropoietic protoporphyria and the very rare congenital protoporphyria and X-linked protoporphyria. Of these, in Finland only erythropoietic protoporphyria has been diagnosed, in which pain and swelling in the skin upon sunlight exposure are the most typical symptoms. A high protoporphyrin level in erythrocytes and a typical peak in the plasma porphyrin spectrum lead to diagnosis.

Vitamin D deficiency in patients with erythropoietic protoporphyria.

BACKGROUND: The main symptom of patients with erythropoietic protoporphyria (EPP) is painful photosensitivity, starting within minutes of sun exposure and leading to sun-avoidance. As 80-100% of vitamin D is synthesized under the influence of sunlight, we investigated whether the avoidance of sunlight exposure in the Dutch EPP patient population causes vitamin D deficiency. Furthermore, we studied the relation between vitamin D levels, total erythrocyte protoporphyrin and quality of life. METHODS: In a cross-sectional study of 48 Dutch EPP patients (mean age 41.4 years; range 16-77; 23 male, 25 female), we assessed serum 25-hydroxyvitamin D (25(OH)D) levels between June and November 2007, as well as total erythrocyte protoporphyrin (TEP) levels and Dermatology Life Quality Index (DLQI) scores. RESULTS: Mean serum 25(OH)D was 66 nmol/L (range 18-140, quartiles 36, 87). Twenty-two patients (46%; 15 male, 7 female) were vitamin D deficient. There was a significant difference (p = 0.029) in mean serum 25(OH)D between female (mean 75 nmol/L, range 18-140) and male patients (mean 55 nmol/L, range 18-115). The level of serum 25(OH)D showed a negative correlation with total erythrocyte protoporphyrin (TEP) (Pearson rank correlation (r(p)) = -0.337; p = 0.034). Serum 25(OH)D was inversely associated with scores of the Dermatology Life Quality Index (DLQI) (Spearman's rho correlation (r(s)) = -0.486; p = 0.001). CONCLUSIONS: The prevalence of vitamin D deficiency is high in the Dutch EPP population, especially in male patients, and correlates with the severity of EPP. Screening for and treatment of vitamin D deficiency should therefore be implemented in the care of these patients.

Porphyria in Switzerland, 15 years experience.

BACKGROUND: The porphyrias, a group of seven metabolic disorders in the haem biosynthesis, can be classified into acute and non-acute porphyrias. A common symptom of acute porphyrias is severe acute abdominal pain, whereas cutaneous photosensitivity can occur in both acute and non-acute porphyrias. All porphyrias, except for sporadic porphyria cutanea tarda (sPCT), are hereditary disorders caused by mutations in the respective genes. We present porphyria cases documented in our porphyria centre during the past 15 years. METHODS: Diagnosis was based on clinical symptoms and biochemical analyses. Mutation analysis was performed in patients/families with a confirmed hereditary porphyria. RESULTS AND CONCLUSIONS: As the porphyria specialist centre of Switzerland, we perform the specialized analyses required for the diagnosis of all types of porphyrias, and give advice to patients, physicians and other laboratories. We therefore estimated that our data cover 80-90% of all diagnosed Swiss cases. A total of 217 patients from 170 families were diagnosed including, 111 acute intermittent porphyria, 45 erythropoietic protoporphyria, 30 variegate porphyria, 21 sPCT, five congenital erythropoietic porphyria, four hereditary coproporphyria and one hepatoerythropoietic porphyria patient. Systematic monitoring of the patients would allow early detection of the potential life-threatening complications such as hepatocellular carcinoma and renal insufficiency in acute porphyrias, and liver failure in EPP. Seventy-five percent of all families underwent genetic testing. Identification of pre-symptomatic mutation carriers so that these individuals and their physicians can be consulted with safety on drug use and other preventive measures, is important in managing acute porphyrias. The unique phenomenon of founder mutations in the Swiss population is also discussed.

Identification of mutations in the uroporphyrinogen III cosynthase gene in German patients with congenital erythropoietic porphyria.

The porphyrias are heterogeneous disorders arising from predominantly inherited catalytic deficiencies of specific enzymes along the heme biosynthetic pathway. Congenital erythropoietic porphyria is a very rare disease that is inherited as an autosomal recessive trait and results from a profound deficiency of uroporphyrinogen III cosynthase, the fourth enzyme in heme biosynthesis. The degree of severity of clinical symptoms mainly depends on the amount of residual uroporphyrinogen III cosynthase activity. In this study, we sought to characterize the molecular basis of congenital erythropoietic porphyria in Germany by studying four patients with congenital erythropoietic porphyria and their families. Using PCR-based techniques, we identified four different mutations: C73R, a well-known hotspot mutation, the promoter mutation -86A that was also described previously, and two novel missense mutations, designated G236V and L237P, the latter one encountered in the homozygous state in one of the patients. Our data from the German population further emphasize the molecular heterogeneity of congenital erythropoietic porphyria as well as the advantages of molecular genetic techniques as a diagnostic tool and for the detection of clinically asymptomatic heterozygous mutation carriers within families.

The penetrance of dominant erythropoietic protoporphyria is modulated by expression of wildtype FECH.

Erythropoietic protoporphyria (EPP) is an inherited disorder of heme biosynthesis caused by a partial deficiency of ferrochelatase (FECH, EC 4.99.1.1). EPP is transmitted as an autosomal dominant disorder with an incomplete penetrance. Using haplotype segregation analysis, we have identified an intronic single nucleotide polymorphism (SNP), IVS3-48T/C, that modulates the use of a constitutive aberrant acceptor splice site. The aberrantly spliced mRNA is degraded by a nonsense-mediated decay mechanism (NMD), producing a decreased steady-state level of mRNA and the additional FECH enzyme deficiency necessary for EPP phenotypic expression.

[Congenital erythropoietic porphyria].

Congenital erythropoietic porphyria (CEP, Günther's disease) is an extremely rare autosomal recessive disease (There have been only 33 case reports in Japan to date.), characterized by mutilating cutaneous photosensitivity and abnormal haem synthesis in the bone marrow. Reduced activity of uroporphyrinogen III synthase (UROIIIS), the fourth enzyme of haem biosynthetic pathway causes this disease. Recent progresses of molecular biology enable us to analyze genetic defect at the molecular level of porphyrias. Also in CEP, it has been reported several reports of mutations of the UROIIIS gene since isolation of a full-length human cDNA encoding UROIIIS by Desnick et al. Here we report about epidemiology, signs and symptoms, laboratory findings and therapies of CEP.