question: Can CD55 deficiency cause thrombosis?
answer: Yes, loss of CD55 is associated with thrombosis in patients with Paroxysmal nocturnal hemoglobinuria. CD55 deficiency with hyperactivation of complement, angiopathic thrombosis, and protein-losing enteropathy (the CHAPLE syndrome) is caused by abnormal complement activation due to biallelic loss-of-function mutations in CD55