[Analysis of 21 cases of Barth syndrome in children].

<b>Objective:</b> To investigate the clinical manifestations, treatment, and outcomes of Barth syndrome (BTHS). <b>Methods:</b> A retrospective analysis was conducted on 21 pediatric patients diagnosed with BTHS between January 2010 and December 2023 at Beijing Children's Hospital, Beijing Anzhen Hospital, and Beijing JingDu Children's Hospital. Clinical data including gender, age at onset, initial symptoms, clinical manifestations, personal history, family genetic history, and laboratory tests (neutrophil count, echocardiography, electrocardiogram and genetic testing) were reviewed. <b>Results:</b> All the 21 patients were male, with the age of onset at 4.1 (1.1, 9.3) months. Main clinical manifestations included heart failure (18 cases), neutropenia (16 cases), respiratory symptoms (15 cases), 3-methylpentenediuria (7 cases),develop retardation (8 cases), gastrointestinal symptoms (7 cases), fatigue and anorexia (6 cases), and recurrent infection (2 cases). Electrocardiogram abnormalities included ST changes (18 cases), flattened T wave and low voltage of limb leads (2 cases), and abnormal Q waves in lead Ⅰ and avL (1 case). Echocardiographic features showed increased trabeculation, interventricular septum and left ventricular wall thickening, and left ventricular enlargement with reduced ejection fraction. Genetic testing identified TAZ gene variations in all 21 patients: 11 missense mutations, 2 nonsense mutations, 2 frameshift mutations, 2 whole code mutations, 2 exon deletions, 1 splicing mutation, and 1 synonymous mutation. Fifteen mutations were maternally inherited, 2 were de novo, and 4 lacked verified variant origin.In terms of treatment, all 18 patients with heart failure received routine heart failure treatment, of whom 11 patients also received intravenous immunoglobulin and corticosteroids. After the follow-up of 91.0 (75.5, 109.5) months, 15 of the 18 patients showed restoration of cardiac function after 4.5 (3.0, 9.8) months of treatment, with one case of significant improvement, while 2 cases suddenly died. <b>Conclusions:</b> BTHS predominantly affects males with early onset, mainly characterized by abnormal cardiac structure and function, along with clinical features including fatigue, delayed growth and development, and neutropenia. Early diagnosis and intervention, including heart failure treatment, intravenous immunoglobulin, and corticosteroids, can lead to significant improvement in cardiac function, though sudden death remains a risk.