Variegate porphyria (VP) causes the abnormal production of heme, an important part of the protein in blood that carries oxygen throughout our bodies. It is used in all the body's organs. Symptoms of VP usually begin in adulthood and are different from person to person. Symptoms may include sun sensitivity and the development of skin blisters and sores when exposed to sunlight. Some people with VP have episodes (acute attacks) of severe stomach pain, nausea and vomiting. In some cases, muscle weakness, anxiety, and seizures may occur. 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. The diagnosis may be confirmed by the results of genetic testing.