Update on the diagnosis and management of the autosomal dominant acute hepatic porphyrias.

The autosomal dominant acute hepatic porphyrias (AHPs), acute intermittent porphyria, hereditary coproporphyria (HCP) and variegate porphyria (VP), are low penetrance adult onset disorders caused by partial deficiency of enzymes of haem biosynthesis. All are associated with acute neurovisceral attacks, which are a consequence of the increased hepatic demand for haem triggered by hormones, stress, drugs or systemic infections which leads to upregulation of the pathway and overproduction of haem precursors 5-aminolaevulinic acid (ALA) and porphobilinogen (PBG). Acute episodes are characterised by severe abdominal pain, nausea, vomiting, hyponatraemia, hypertension and tachycardia, behavioural disturbance and can progress to include seizures, peripheral motor neuropathy and posterior reversible encephalopathy syndrome if undiagnosed and untreated.

EXPLORE: A Prospective, Multinational, Natural History Study of Patients with Acute Hepatic Porphyria with Recurrent Attacks.

Background And Aims: Acute hepatic porphyria comprises a group of rare genetic diseases caused by mutations in genes involved in heme biosynthesis. Patients can experience acute neurovisceral attacks, debilitating chronic symptoms, and long-term complications. There is a lack of multinational, prospective data characterizing the disease and current treatment practices in severely affected patients.

International Porphyria Molecular Diagnostic Collaborative: an evidence-based database of verified pathogenic and benign variants for the porphyrias.

With the advent of precision and genomic medicine, a critical issue is whether a disease gene variant is pathogenic or benign. Such is the case for the three autosomal dominant acute hepatic porphyrias (AHPs), including acute intermittent porphyria, hereditary coproporphyria, and variegate porphyria, each resulting from the half-normal enzymatic activities of hydroxymethylbilane synthase, coproporphyrinogen oxidase, and protoporphyrinogen oxidase, respectively. To date, there is no public database that documents the likely pathogenicity of variants causing the porphyrias, and more specifically, the AHPs with biochemically and clinically verified information.

An Audit of the Use of Gonadorelin Analogues to Prevent Recurrent Acute Symptoms in Patients with Acute Porphyria in the United Kingdom.

Severe recurrent acute attacks of porphyria have traditionally been treated with either prophylactic human haemin or gonadorelin analogues (GnA) in females. Evidence on the most effective treatment for this patient subgroup is lacking. This audit surveyed the use of prophylactic GnA in the UK.

Update review of the acute porphyrias.

Acute porphyrias are rare inherited disorders due to deficiencies of haem synthesis enzymes. To date, all UK cases have been one of the three autosomal dominant forms, although penetrance is low and most gene carriers remain asymptomatic. Clinical presentation is typically with acute neurovisceral attacks characterised by severe abdominal pain, vomiting, tachycardia and hypertension.

Best practice guidelines on first-line laboratory testing for porphyria.

The porphyrias are disorders of haem biosynthesis which present with acute neurovisceral attacks or disorders of sun-exposed skin. Acute attacks occur mainly in adults and comprise severe abdominal pain, nausea, vomiting, autonomic disturbance, central nervous system involvement and peripheral motor neuropathy. Cutaneous porphyrias can be acute or chronic presenting at various ages.

Bovine congenital erythropoietic protoporphyria in a crossbred limousin heifer in Ireland.

An unusual case of an 11-month-old, black Limousin-cross heifer, with an 8-month history of episodic seizures and photosensitisation, was referred by a veterinary practitioner to the Farm Animal Section of the UCD Veterinary Hospital, School of Veterinary Medicine, University College Dublin, Ireland, in August 2014. Following an investigation, a diagnosis of Bovine Congenital Erythropoietic Protoporphyria (BCEPP) was made. To the authors' knowledge this is the first report of such a case in Ireland.

Audit of the Use of Regular Haem Arginate Infusions in Patients with Acute Porphyria to Prevent Recurrent Symptoms.

The National Acute Porphyria Service (NAPS) provides acute care support and clinical advice for patients in England with active acute porphyria requiring haem arginate treatment and patients with recurrent acute attacks.This audit examined the benefits and complications of regular haem arginate treatment started with prophylactic intent to reduce the frequency of recurrent acute attacks in a group of patients managed through NAPS. We included 22 patients (21 female and 1 male) and returned information on diagnosis, indications for prophylactic infusions, frequency and dose, analgesia, activity and employment and complications including thromboembolic disease and iron overload.

Best practice guidelines on clinical management of acute attacks of porphyria and their complications.

The British and Irish Porphyria Network guidelines describe best practice in the clinical assessment, investigation and management of acute porphyria attacks and their complications, including severe attacks with neuropathy. Acute attacks of porphyria may occur in acute intermittent porphyria (AIP), variegate porphyria (VP) and hereditary coproporphyria (HCP). Aminolaevulinic acid dehydratase deficiency porphyria (ADP) is a very rare autosomal recessive porphyria; only six cases substantiated by mutation analysis have yet been described in the literature.

The incidence of inherited porphyrias in Europe.

Retrospective estimates of the prevalence of porphyrias have been reported but there has been no large scale prospective study of their incidence. The European Porphyria Network collected information prospectively over a 3 year period about the number of newly diagnosed symptomatic patients with an inherited porphyria (335 patients from 11 countries). Prevalence was calculated from the incidence and mean disease duration.

Congenital erythropoietic porphyria: a single-observer clinical study of 29 cases.

Background: Congenital erythropoietic porphyria (CEP) is an autosomal recessive cutaneous porphyria caused by decreased activity of uroporphyrinogen III synthase (UROS). Its predominant characteristics include bullous cutaneous photosensitivity to visible light from early infancy, progressive photomutilation and chronic haemolytic anaemia. Due to its rarity and genetic heterogeneity, clinical phenotypes are unclear and its impact on health-related quality of life (HRQoL) has not been previously assessed.

A management algorithm for congenital erythropoietic porphyria derived from a study of 29 cases.

Background: Congenital erythropoietic porphyria (CEP) is an autosomal recessive photomutilating porphyria with onset usually in childhood, where haematological complications determine prognosis. Due to its extreme rarity and clinical heterogeneity, management decisions in CEP are often difficult.

Objectives: To develop a management algorithm for patients with CEP based on data from carefully characterized historical cases.

Acute intermittent porphyria: fatal complications of treatment.

Acute neurovisceral attacks of porphyria can be life threatening. They are rare and notoriously difficult to diagnose clinically, but should be considered, particularly in female patients with unexplained abdominal pain, and associated neurological or psychiatric features or hyponatraemia. The diagnosis might be suggested by altered urine colour and can be confirmed by finding an elevated porphobilinogen concentration in fresh urine protected from light.

European specialist porphyria laboratories: diagnostic strategies, analytical quality, clinical interpretation, and reporting as assessed by an external quality assurance program.

Background: The porphyrias are a group of rare metabolic disorders whose diagnosis depends on identification of specific patterns of porphyrin precursor and porphyrin accumulation in urine, blood, and feces. Diagnostic tests for porphyria are performed by specialized laboratories in many countries. Data regarding the analytical and diagnostic performance of these laboratories are scarce.

Liver transplantation for acute intermittent porphyria is complicated by a high rate of hepatic artery thrombosis.

Acute intermittent porphyria (AIP) is an autosomal-dominant condition resulting from a partial deficiency of the ubiquitously expressed enzyme porphobilinogen deaminase. Although its clinical expression is highly variable, a minority of patients suffer recurrent life-threatening neurovisceral attacks despite optimal medical therapy. Because the liver is the major source of excess precursor production, liver transplantation (LT) represents a potentially effective treatment for severely affected patients.