E78.71 Barth syndrome

Name of the Condition

• Barth syndrome

Summary

Barth syndrome is a rare genetic disorder characterized by cardiomyopathy, neutropenia, skeletal myopathy, and growth delay. It primarily affects males and is caused by mutations in the TAZ gene, which disrupts mitochondrial function and lipid metabolism. The condition can lead to heart failure, recurrent infections, and muscle weakness, with symptoms varying in severity among individuals.

Causes

Barth syndrome is caused by mutations in the TAZ gene, which provides instructions for producing tafazzin, an enzyme involved in cardiolipin remodeling within mitochondria. This disruption impairs mitochondrial function, leading to the characteristic symptoms. The condition is inherited in an X-linked recessive pattern, meaning it primarily affects males, while females are typically carriers.

Risk Factors

• Male sex (due to X-linked inheritance).
• Family history of Barth syndrome or related mitochondrial disorders.
• Presence of TAZ gene mutations in the family.

Symptoms

Symptoms may include cardiomyopathy (especially dilated cardiomyopathy), neutropenia (low neutrophil count leading to recurrent infections), skeletal myopathy (muscle weakness), growth delay, and fatigue. Some individuals may also experience metabolic abnormalities, such as 3-methylglutaconic aciduria, and cardiac arrhythmias.

Diagnosis

Diagnosis is based on clinical presentation, family history, and laboratory tests. Blood tests may reveal neutropenia, elevated 3-methylglutaconic acid, and abnormal lipid profiles. Genetic testing for TAZ gene mutations confirms the diagnosis. Cardiac evaluations, including echocardiography, assess heart function, while muscle biopsies may show mitochondrial abnormalities.

Treatment Options

Treatment focuses on managing symptoms and complications. Cardiomyopathy may require medications (e.g., ACE inhibitors, beta-blockers) or heart transplantation in severe cases. Neutropenia is managed with antibiotics for infections and granulocyte colony-stimulating factor (G-CSF) to boost neutrophil counts. Physical therapy addresses muscle weakness, and nutritional support aids growth.

Prognosis and Follow-Up

Prognosis varies; some individuals experience mild symptoms, while others face life-threatening complications like heart failure. Regular follow-up with cardiologists, hematologists, and geneticists is essential. Monitoring cardiac function, infection risk, and growth helps guide management. Early intervention improves outcomes, but long-term prognosis depends on symptom severity.

Complications

Complications include heart failure, life-threatening infections due to neutropenia, arrhythmias, and developmental delays. Skeletal muscle weakness may limit mobility, and metabolic abnormalities can contribute to organ dysfunction over time.

Lifestyle & Prevention

While prevention is not possible due to genetic causes, lifestyle measures support management. Avoiding infections through hygiene and vaccinations reduces neutropenia-related risks. Regular exercise (as tolerated) and a balanced diet support muscle and cardiac health. Genetic counseling is recommended for families to understand inheritance risks.

When to Seek Professional Help

Seek immediate care for signs of infection (fever, chills), chest pain, or breathing difficulties. Routine follow-up is necessary for monitoring cardiac function, neutrophil counts, and growth. Consult a specialist if symptoms worsen or new complications arise.

Tips for Medical Coders

Document the presence of cardiomyopathy, neutropenia, myopathy, or growth delay to support coding. Include genetic confirmation of TAZ mutations when available. Specify if cardiac complications (e.g., heart failure) or infections are present, as these may require additional coding. Ensure documentation aligns with clinical findings to accurately reflect the condition’s impact.