What exactly causes porphyria? As it was said above, the disease is inherited meaning it is passed via genes. It does not mean, however, the individual cannot gain the disease during the lifetime. In most cases, the patient inherits the ‘bad’ gene just from one parent. It means that the disease belongs to the so-called autosomal dominant group of diseases. As for the other causes, the list includes alcohol beverages, external infections, viruses, specific hormonal changes, dangerous medications, and sunlight. The causes also predetermine the type of hepatic form of porphyria. This type can be divided into the acute, hereditary, variegated, and aminolevulinic acid dehydratase deficiency.