Porphyria variegata (PV) is caused by a defect in the PPOX gene which codes for protoporphyrinogen oxidase. A defect in this enzyme results in accumulation of the porphyrin precursors porphobilinogen and 5-aminolevulinic acid in plasma; increase of fecal and urinary levels of porphyrin and coproporphyrin. Symtpoms include abdominal pain, vomiting, diarrhea, constipation, muscle weakness, seizures, and mental changes such as anxiety and hallucinations. Some people with variegate porphyria have skin that is overly sensitive to sunlight. Areas of skin exposed to the sun develop severe blistering, scarring, changes in pigmentation, and increased hair growth.