What are the genetic changes related to familial dysautonomia ?
Mutations in the IKBKAP gene cause familial dysautonomia.  The IKBKAP gene provides instructions for making a protein called IKK complex-associated protein (IKAP). This protein is found in a variety of cells throughout the body, including brain cells.  Nearly all individuals with familial dysautonomia have two copies of the same IKBKAP gene mutation in each cell. This mutation can disrupt how information in the IKBKAP gene is pieced together to make a blueprint for the production of IKAP protein. As a result of this error, a reduced amount of normal IKAP protein is produced. This mutation behaves inconsistently, however. Some cells produce near normal amounts of the protein, and other cellsparticularly brain cellshave very little of the protein. Critical activities in brain cells are probably disrupted by reduced amounts or the absence of IKAP protein, leading to the signs and symptoms of familial dysautonomia.