Paroxysmal nocturnal hemoglobinuria (PNH) also called Marchiafava-Micheli syndrome (from the name of Dr. Ettore Marchiafava and Dr. Ferdinando Micheli) For every million people only a few suffer from paroxysmal nocturnal hemoglobinuria which makes this is a rare blood disorder. Paroxysmal nocturnal hemoglobinuria affects both sexes and all ages equally. PNH patients suffer from a defective or missing PGI-A gene found in erythrocytes, leukocytes, and thrombocytes. Paroxysmal nocturnal hemoglobinuria is not a hereditary disease but is considered an acquired disease because the hematopoietic stem cells begin to change and function poorly over time. This process of cellular change is called somatic mutation. While not all blood cells will have this faulty gene, those that do will only be able to produce more mutated cells creating a cycle of increase in damaged cells that continues to expand. The number of mutated cells a person with this disease has is what determines the degree to which they will suffer symptoms. As the number of PNH cells increases, the symptoms also increase. The PIG-A gene also plays a role in sending signals to the body about how to make GPI anchors that attach complement-regulating proteins to blood cell membranes. When these protective proteins lack the ability to stick together, they leave blood cells vulnerable to attack by the body's immune system. Without the proteins that regulate the immune system, the immune system reacts as if the cells were an infection or bacteria and destroys them. When the body does not have enough red blood cells the condition is called hemolytic anemia. PNH also damages platelets (thrombocytes) by interfering with their ability to form blood clots, due to... half of the paper ......destroys PNH by transplanting healthy marrow (most often from a relative) into the patient . There is a VERY high mortality rate with this treatment, so it is generally reserved for patients who suffer from PNH along with another disease such as leukemia, aplastic anemia, or myelodysplastic syndrome, and all other treatment options are not more sufficient. Works Cited http:// www.ncbi.nlm.nih.gov/books/NBK22166/http://ghr.nlm.nih.gov/condition/paroxysmal-nocturnal-hemoglobinuriahttp://www.nlm.nih.gov/ medlineplus/ency/article/ 003642.htmhttp://www.nlm.nih.gov/medlineplus/ency/article/000534.htmhttp://en.wikipedia.org/wiki/Paroxysmal_nocturnal_hemoglobinuria#Treatmenthttp://rarediseases.info. nih.gov/GARD/ Disease.aspx?PageID=4&DiseaseID=7337http://bloodjournal.hematologylibrary.org/content/113/26/6522.fullhttp://www.haematologica.org/cgi/content/full/95/6/855