Barth syndrome is a rare condition characterized by an enlarged and weakened heart (dilated cardiomyopathy), weakness in muscles used for movement (skeletal myopathy), recurrent infections due to small numbers of white blood cells (neutropenia), and short stature. Barth syndrome occurs almost exclusively in males.

Mutations in the TAFAZZIN gene cause Barth syndrome. The TAFAZZIN gene provides instructions for making a protein called tafazzin. This protein is located in structures called mitochondria, which are the energy-producing centers of cells. The tafazzin protein is involved in altering a fat (lipid) called cardiolipin, which plays critical roles in the mitochondrial inner membrane. Once altered by tafazzin, cardiolipin is key in maintaining mitochondrial shape, energy production, and protein transport within cells.

Barth syndrome is estimated to affect 1 in 300,000 to 400,000 individuals worldwide. More than 150 cases have been described in the scientific literature.

This condition is inherited in an X-linked recessive pattern. The gene associated with this condition is located on the X chromosome, which is one of the two sex chromosomes. In males (who have only one X chromosome), one altered copy of the gene in each cell is sufficient to cause the condition. In females (who have two X chromosomes), a mutation would have to occur in both copies of the gene to cause the disorder. Because it is unlikely that females will have two altered copies of this gene, males are affected by X-linked recessive disorders much more frequently than females. A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons.

Published Date: November 24, 2021
Published By: National Institutes of Health