It is an autosomal recessive disorder which means that every individual that is affected has inherited one copy of the genetic mutation from each of his parents. People who have only one copy of the mutation are known as carriers and since they are unaffected, are not aware they have the mutation until they have a child with familial dysautonomia.
Chromosomes are the blueprint for how a body s cells develop and function.
Every person has 23 pairs of chromosomes. One chromosome of each pair is inherited from one s mother and the other chromosome is inherited from one s father. Sections of the DNA strands which make proteins are called genes. It is our genes that determine how certain traits will be expressed and tell our body s cells how to function. When there is an error within a portion of a gene s DNA, it is called a mutation and the gene does not function the way it should.