Eponym: Barth syndrome.

UNLABELLED: Barth syndrome (OMIM #302060) (BTHS) is an X-linked disorder of lipid metabolism characterized by skeletal myopathy, neutropenia, growth delay, and cardiomyopathy. It is caused by mutations in the tafazzin gene (TAZ), which lead to decreased production of an enzyme required to produce cardiolipin, a component of the inner mitochondrial membrane necessary for proper functioning of the electron transport chain. The most common initial presentation of BTHS is significant heart failure due to cardiomyopathy, which is the main cause of death in infancy or childhood. On the other hand, some patients have limited clinical features of BTHS. These patients may be overlooked or misdiagnosed with unclassified congenital myopathy, especially when heart failure is not clinically significant. However, these patients could also develop significant heart failure or life-threatening arrhythmias during or even after childhood. Heart failure in BTHS is often responsive to standard medical therapy, indicating early diagnosis is critical. Diagnostic clues of BTHS in the subclinical stage of heart failure include family histories, findings of lipid storage myopathy in the skeletal muscle biopsy, and elevated plasma brain natriuretic peptide levels. The genetic analysis of TAZ is the only confirmatory method for the diagnosis of BTHS. CONCLUSION: physicians should be aware of the possibility of this disease and carry out genetic studies when it is considered.