It has been shown in some scientific studies that lack of CD59 in the context of the disease paroxysmal nocturnal hemoglobinuria (PNH)leads to chronic hemolysis. The investigators have identified patients wirh CD59 deficiency that suffers from chronic hemolysis and demyelinating disease. It was shown that complement terminal pathway can cause cause inflammation in nervous system. Complement can greatly increase the immune attack in the nerves. Eculizumab has already been shown to be effective in a rare blood disorder known as PNH. Attacks of PNH are also mediated through complement. Therefore, the investigators of this study are investigating whether by 'turning off' complement in CD59 deficiency, further attacks of hemolysis and nerve injury can be avoided.