What is (are) Porphyria ?
Porphyrias are rare disorders that affect mainly the skin or nervous system and may cause abdominal pain. These disorders are usually inherited, meaning they are caused by abnormalities in genes passed from parents to children. When a person has a porphyria, cells fail to change body chemicals called porphyrins and porphyrin precursors into heme, the substance that gives blood its red color. The body makes heme mainly in the bone marrow and liver. Bone marrow is the soft, spongelike tissue inside the bones; it makes stem cells that develop into one of the three types of blood cellsred blood cells, white blood cells, and platelets.
                
The process of making heme is called the heme biosynthetic pathway. One of eight enzymes controls each step of the process. The body has a problem making heme if any one of the enzymes is at a low level, also called a deficiency. Porphyrins and porphyrin precursors of heme then build up in the body and cause illness.