| Erythropoietic Protoporphyria (EPP) |
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What is EPP?EPP an autosomal dominant or autosomal recessive metabolic disease. It is a rare disease that occurs in about 1:100.000 persons. It is so rare that most people or even doctors have not ever heard or know about it. It was discovered and written about in 1961 in England.EPP is one of the different types of porphyria. In contrast to other porphyrias it does not occure with acute attacks, but is more a chronic condition. Below is more information about the disease by subject. Additional and more elaborate information can also be found under links to the left: 'info for patients, family and friends, medical professional.' SYMPTOMS Patients also EPP patients are very sensitive to visible light (especially the blue and green rays). When they are exposed to sunlight, strong light or lamps, they can get pain and itching that can remain for hours or sometimes even days after exposure.have to be carefull for exposure to licht that comes through windows or is reflected from objects likemirrors, smooth surfaces and parasols. Some patients are also sensitive for strong lamps, for example fluorescent lamps, energy saving lamps and industrial lamps. The patients symptoms are not always visible, however, the surface of the skin can become red and swollen while the underneath the surface it can become infected. Patients may have acute episodes of burning and pains and itches. After a prolonged time of exposure to sunlight, they can get blisters and scarring as well as an increase in hairgrowth and pigmentation. Some patients are susceptable to gallstones caused by accumulations of protoporphyrins. A small group of patients develop liver disease and liver damage. CAUSES While EPP is not a skin disease but a metabolic disease, most patients end up for treatment and/or diagnosis by a dermatologist. Symptoms are sometimes visible or appear as a skin problem while the cause is actually found in a chemical process in the bonemarrow called haemsynthesis. Red bloodcells are made in the bonemarrow. Haem is the end product of haemsynthesis. In EPP, there is usually a shortage of an enzyme (a protein which helps convert one chemical substance into another), called ferrochelatase (FECH), that adds iron to protoporphyrin to make haem. By the EPP patient is the last step in the process to create haem disrupted resulting in the accumulation of protoporphyrins in the body (the red bloodcells, bonemarrow, de gallbladder and sometimes the liver). Protoporphyrins are not water soluable and cannot be transported via the urine outside the body causing therefore a accumulation of protoporphyrins in the body. Since protoporphyrins are photoreactive, EPP patients become therefore extremely sensitive for light. INHERITANCE EPP is an autosomal dominant inherited disease with low penetration. In the past, it was thought that EPP had a high inherited trait, in other words, it was thought that EPP had a 50% posterity rate. After many studies and research in the inheritance trait of EPP it was discovered that EPP had a autosomal dominant trait with low penatration. To understand what this means, we will start with a short explanation about inheritance and DNA. Our body is made out of cells. Every cell is made out of building blocks of our body that we know as DNA. DNA is made out 46 chromosomes divided in 23 pairs. Every human has the first 22 pairs the same. The last and 23rd pair is by women a XX pair and by men a XY pair. The father passes on 23 chromosomes and the mother passes on 23 chromosomes to make again a total of 46 chromosomes. A chromosome is divided into two parts, called chromatides. Every chromatide has a number of genes with inherited data. Every gene has two or more parts called alleles. In EPP the allele is dominant with low penetration. So every allele with the EPP gene is dominant over the other allele called recessive. Through research was discovered that the EPP gene is not completely dominant. Some patients inherit EPP through 1 gene inheritance, however, research determined most patients needed a 2 gene inheritance with an additional splice variation. This variation with a still unknown factor is found in about 10% of the population. So depending on which gene was inherited, one can be an EPP patient or an EPP carrier without symptoms.  DIAGNOSIS EPP is diagnosed in patient with light sensitivity through the testing of bloodplasma and feces by looking for the presence of abnormal high values of protoporphyrins. Not like the other porphyrias, in EPP the porphyrine level stays normal in the urine of the patient. Some family member of an EPP patient have a slight higher level or protoporphyrines in their blood but have no symptoms. This suggest the excistance of the possiblity of EPP carriership. TREATMENT At this time, there is no cure for EPP. The most important treatment is to protect the exposed skin from light. EPP patients must protect their exposed skin throught extra protective layers of clothing, gloves, hats and caps, and sunglasses. Clothes made of natural materials, especially jeans, provide better protection than polyesters. Special anti-UV window treatments are also very important. A high factor sunscreen (europe 50+, states 85+ minimum) anti UV-A and UV-B is recommend, however, not all patients will benefit from it. A sunscreen does not protect for the higher radiations for which most EPP patients are just the most sensitivity to. Some patients can decrease their sensitivity by taking high dosis of pure beta-carotene (50 to 180 mg). Be aware that carotene can cause the skin to turn orange. At this moment beta-carotene is not covered in Belgium. Some patients develop liver problems because of the accumulation of protoporphyrins. In addition, possible risk factors for liver disease should be avoided. This means that patients should avoid fasting, alcoholic beverages, barbiturates, sulfonamides, estrogen compounds and birth control pills. Some patients have reported an increase in sensitivity after drinking alcohol. Therefore, it is strongly recommended to avoid drinking alcohol. |