Variegate Porphyria (VP)

Read about CLINUVEL’s program for variegate porphyria here.

Snapshot
Other common terms: VP
ICD-10 classification: E80.2
Prevalence: 1:100,000 in European countries
Causes: Inherited disease; defective enzyme causes inability to properly produce haem.
Symptoms: Blistering lesions, chronic fragility of sun and light-exposed skin, especially the back of the hands and the face. Lesions are slow to health or do not at all, and are prone to infection.
Treatments/cures: No standard care or therapy.
Differential diagnosis: Other porphyrias.

Variegate porphyria (VP) is a rare autosomal dominant inherited disorder resulting from the deficiency of the mitochondrial enzyme protoporphyrinogen oxidase (PPOX), the sixth enzyme of the haem biosynthesis pathway.

A debilitating and burdensome disease for patients, VP is classified as both a cutaneous and acute porphyria. The cutaneous symptoms are characterised by adult-onset blistering lesions (bullous symptoms, subepidermal vesicles) and chronic fragility (hypotrophy and hypoplasia) of sun and light-exposed skin, especially the back of the hands and the face. The propensity of the dermis to form wounds (lesions and erosions which form crusts, heal slowly or not at all, and are prone to infection) following the mechanical use of hands and feet further restricts VP patients in their daily activities.

Incidence

The reported prevalence of VP varies from 0.3 to 2 cases per 100,000 inhabitants but has been reported as more common in the Caucasian South African population (up to 1 in 300 people) due to a founder effect. European prevalence varies from 0.32 to 1 cases per 100,000 inhabitants, whereas the reported prevalence in the US is 0.5 cases per 100,000 inhabitants.

Symptoms

Typically, patients experience scarring of the face, hands and feet. Patients diagnosed with VP experience phototoxicity and suffer episodes in spring and summer when the atmospheric intensity of light increases. The acute neurovisceral symptoms may present as severe episodes as early as adolescence, with women more affected than men. Psychiatric disturbances, autonomic neuropathy and muscle weakness have been reported in some patients.

Treatments

Currently, there is no standard of care or alternative therapy for cutaneous VP symptoms. Patients are forced to lead a life sheltered from light and to avoid any mechanical contact with their skin surface or risk of triggering wounds and long-lasting blistering.