What type of mutation causes porphyria?

Each type of porphyria is caused by a mutation, or change, in the gene coding for a specific enzyme in the heme pathway….Inheritance of the Porphyrias.

What is porphyria variegata?

Disease definition. Variegate porphyria is a form of acute hepatic porphyria (see this term) characterized by the occurrence of neuro-visceral attacks with or without the presence of cutaneous lesions.

What protein does porphyria affect?

Heme is a component of hemoglobin, the protein in red blood cells that carries oxygen from your lungs to all parts of your body. Heme production, which occurs in the bone marrow and liver, involves eight different enzymes — a shortage (deficiency) of a specific enzyme determines the type of porphyria.

What is the most common cause of acquired porphyria?

This shortage leads to a buildup of certain chemicals, called porphyrins, that help make heme. The type of porphyria you have is linked to the specific enzyme that your body lacks. Most types of porphyria are inherited. That means one or both of your parents passes a mutated gene to you that leads to the disease.

What is the rarest form of porphyria?

Congenital erythropoietic porphyria is a very rare inherited metabolic disorder resulting from the deficient function of the enzyme uroporphyrinogen III synthase (UROS), the fourth enzyme in the heme biosynthetic pathway.

Why is urine purple in porphyria?

The terms porphyrin and porphyria are derived from the Greek word porphyrus, meaning purple. Urine from some Porphyria patients may be reddish-purple in color due to the presence of excess porphyrins and related substances in the urine, and the urine may darken after exposure to light.

What are the causes of variegate porphyria ( VP )?

Variegate porphyria is caused by genetic changes in the PPOX gene and is inherited in an autosomal dominant pattern. Some people who have PPOX gene variants never have symptoms of porphyria. Diagnosis of VP is based on the symptoms, clinical examination, and other blood and urine tests.

Who are the variegate porphyria children in South Africa?

Four South African children manifesting variegate porphyria were compound heterozygotes with the founder mutation on one allele, but a different mutation apparently encoding an enzyme with enough residual activity to enable survival, on the other. [ 15]

Are there any treatments for variegate porphyria tarda?

Treatments that are effective in porphyria cutanea tarda, namely phlebotomies and low-dose hydroxychloroquine or chloroquine, are not useful in variegate porphyria because, even though the skin abnormalities are the same, the underlying abnormalities in the liver are very different.

What causes abnormally high levels of porphyrin precursors?

The porphyrias are characterized by abnormally high levels of porphyrins or porphyrin precursors in the body. Each porphyria is due to a deficiency of a different enzyme. There are eight enzymes in the pathway for making heme, which is a part of hemoglobin and other hemoproteins.