What causes Porphyria ?
Most porphyrias are inherited disorders. Scientists have identified genes for all eight enzymes in the heme biosynthetic pathway. Most porphyrias result from inheriting an abnormal gene, also called a gene mutation, from one parent. Some porphyrias, such as congenital erythropoietic porphyria, hepatoerythropoietic porphyria, and erythropoietic protoporphyria, occur when a person inherits two abnormal genes, one from each parent. The likeliness of a person passing the abnormal gene or genes to the next generation depends on the type of porphyria.
                
Porphyria cutanea tarda is usually an acquired disorder, meaning factors other than genes cause the enzyme deficiency. This type of porphyria can be triggered by
                
- too much iron  - use of alcohol or estrogen  - smoking  - chronic hepatitis Ca long-lasting liver disease that causes inflammation, or swelling, of the liver  - HIVthe virus that causes AIDS  - abnormal genes associated with hemochromatosisthe most common form of iron overload disease, which causes the body to absorb too much iron
                
For all types of porphyria, symptoms can be triggered by
                
- use of alcohol  - smoking  - use of certain medications or hormones  - exposure to sunlight  - stress  - dieting and fasting