This disease is thought to be very rare. However, as is often the case with rare disorders, increased awareness of the disorder among medical practitioners and the public may lead to increased reports of its incidence. Since so little is known about Barth Syndrome at the biochemical and molecular level, it is possible that many cases go undetected. At present, there are known to be two families with affected family members in Australia, and a few dozen in the United States, Canada, and Europe. A recent paper from England found 5 new boys with Barth syndrome in one hospital in 7 years.
Males carrying the altered gene are likely to be affected.
However, not every mother of an affected boy is a carrier for Barth Syndrome. Sometimes boys are affected because of a new mutation on their X chromosome. Research investigators often give genes affectionate or in-house names. BTHS is the official genome name of the gene that when altered, causes Barth Syndrome. Another name that has been used is G4.5.