What are the genetic changes related to moyamoya disease ?
The genetics of moyamoya disease are not well understood. Research suggests that the condition can be passed through families, and changes in one gene, RNF213, have been associated with the condition. Other genes that have not been identified may be involved in moyamoya disease. It is also likely that other factors (such as infection or inflammation) in combination with genetic factors play a role in the condition's development.  The RNF213 gene provides instructions for making a protein whose function is unknown. However, research suggests that the RNF213 protein is involved in the proper development of blood vessels.  Changes in the RNF213 gene involved in moyamoya disease replace single protein building blocks (amino acids) in the RNF213 protein. The effect of these changes on the function of the RNF213 protein is unknown, and researchers are unsure how the changes contribute to the narrowing of blood vessels or the characteristic blood vessel growth of moyamoya disease. For unknown reasons, people with moyamoya disease have elevated levels of proteins involved in cell and tissue growth, including the growth of blood vessels (angiogenesis). An excess of these proteins could account for the growth of new blood vessels characteristic of moyamoya disease. It is not clear if changes in the RNF213 gene are involved in the overproduction of these proteins.