Barth syndrome

Lore & Background

Dr. Peter Barth, a Dutch pediatric neurologist born in 1932, identified the syndrome in 1983 by describing a pedigree chart that demonstrated the inherited nature of the condition, distinguishing it from infectious diseases. His work established the genetic basis of the disorder, which was later linked to mutations in the TAFAZZIN gene located at Xq28. The gene product, tafazzin, functions as an acyltransferase in complex lipid metabolism, and its deficiency leads to cardiolipin abnormalities within mitochondria.

The syndrome manifests primarily in males due to its X-linked inheritance, with females typically being asymptomatic carriers. Clinical presentation is highly variable, but early-onset cardiomyopathy is a common denominator. Neutropenia, though severe, is associated with relatively fewer bacterial infections compared to non-Barth patients with neutropenia. Growth delay is typical in childhood, but many patients reach normal adult height after puberty.

Diagnosis involves blood tests, urinalysis, echocardiography, and DNA sequencing of TAFAZZIN. Treatment options are supportive and include management of cardiomyopathy, infections, and growth issues; elamipretide (Forzinity) has not received FDA approval for Barth syndrome as of the current knowledge cutoff. The syndrome is believed to be under-reported due to diagnostic complexity, with cases documented across multiple continents.

Reader's Guide

Barth syndrome is significant as a model for understanding mitochondrial lipid metabolism and its role in cardiac and immune function. The discovery of the TAFAZZIN gene and its product, tafazzin, has advanced knowledge of cardiolipin synthesis and mitochondrial membrane dynamics. The syndrome's variable phenotype, even among siblings, underscores the importance of genetic testing over symptomatology alone for diagnosis. Its X-linked inheritance pattern necessitates careful familial history-taking and testing of matrilineal male relatives. The approval of elamipretide in 2025 marks a therapeutic milestone, though the condition remains ultra-rare and potentially fatal. The syndrome's association with stillbirth and its heterogeneous presentation highlight the need for early diagnosis to manage cardiomyopathy and neutropenia. Barth syndrome also provides insights into related conditions such as 3-methylglutaconic aciduria and noncompaction cardiomyopathy.

Did You Know?

• Barth syndrome is diagnosed almost exclusively in males due to its X-linked inheritance.
• Cardiomyopathy in Barth syndrome commonly resolves or substantially improves after puberty.
• Every patient tested by Dr. Kulik in 2008 had abnormalities in cardiolipin, a mitochondrial lipid.