Barth syndrome is an X-linked recessive condition caused by defective remodelling of cardiolipins in mitochondrial membranes because of mutations in the tafazzin (TAZ1/G4.5) gene located at Xq28. The cardinal features of Barth syndrome are cardiac and skeletal myopathy and neutropaenia, reported in the initial description of this condition by Barth et al. (J Neurol Sci 62:327-355) in 1983. Many features of the Barth phenotype have been described but there is no published comment on the facial appearance of these boys, which is consistent and characteristic of this condition.