Barth syndrome

Barth syndrome is inherited in an X-linked recessive manner. This means the gene associated with it, called tafazzin (TAZ), is on the X-chromosome. Females usually have two X-chromosomes and males have one. People with Barth syndrome have a change, or mutation, in the tafazzin gene on one of their X-chromosomes. Since males only have one X-chromosome to begin with, they are more likely to have symptoms of Barth syndrome if they have a tafazzin gene mutation -- they have no "back-up" gene on a second X-chromosome. Females have that "back-up" second X-chromosome and are often protected from symptoms of Barth syndrome for this reason. Females who have a tafazzin gene mutation on one of their X-chromosomes are known as Barth syndrome "carriers" and can have sons with Barth syndrome and daughters that are Barth syndrome carriers in the future.