Confidence votes 11. According to Wikipedia, the width of the Atlantic Ocean at its narrowest point is 2,848 kilometers (1,770 mi) between Brazil and Sierra Leone.
What causes PNH? It is not fully understood why people develop PNH. Inside the bone marrow, blood cells are made by stem cells (the seed cells of the marrow). PNH occurs due to a change (or mutation) in a gene in one of the stem cells in the bone marrow. This mutation happens in a gene called PIG-A and the cells made by this stem cell lack certain proteins on their surface making them âweakerâ than normal blood cells.
Because PNH is. thought to come from an injury to a blood stem cell (a cell in. your bone marrow which produces other cells), PNH can devel-. op in all three types of blood cells â red blood cells which carry. oxygen to your body, white blood cells which help fight infec-.