H49.813 Kearns-Sayre syndrome, bilateral

Name of the Condition

• Kearns-Sayre syndrome, bilateral

Summary

Kearns-Sayre syndrome is a rare mitochondrial disorder characterized by progressive external ophthalmoplegia (weakness of the eye muscles), pigmentary retinopathy, and cardiac conduction defects. This specific code applies to manifestations affecting both eyes. The condition typically presents before age 20 and may involve systemic manifestations such as ataxia, hearing loss, or endocrine abnormalities. It is caused by deletions in mitochondrial DNA and follows a progressive course.

Causes

Kearns-Sayre syndrome is caused by large deletions in mitochondrial DNA, which disrupt energy production in cells. These deletions are usually sporadic and not inherited from parents. The exact trigger for these deletions is not fully understood, but they result in impaired mitochondrial function affecting multiple organ systems, including the ocular structures.

Risk Factors

• Age of onset (typically before 20 years)
• Sporadic mitochondrial DNA deletions
• Family history of mitochondrial disorders (rare)

Symptoms

• Progressive external ophthalmoplegia (eye muscle weakness) affecting both eyes
• Pigmentary retinopathy (retinal changes) in both eyes
• Cardiac conduction defects (e.g., heart block)
• Ataxia (loss of coordination)
• Hearing loss
• Endocrine abnormalities (e.g., diabetes, thyroid issues)
• Short stature
• Cognitive impairment (in some cases)

Diagnosis

Diagnosis is based on clinical features (ophthalmoplegia, retinopathy, cardiac conduction defects) and confirmed by genetic testing showing mitochondrial DNA deletions. Additional tests may include electrocardiography (ECG) for cardiac conduction abnormalities, brain MRI for central nervous system involvement, and endocrine evaluations. Muscle biopsy may reveal ragged-red fibers, though this is less commonly performed now with genetic testing availability.

Treatment Options

Treatment focuses on managing symptoms and preventing complications. This may include cardiac pacing for conduction defects, endocrine hormone replacement, physical therapy for ataxia, and regular monitoring of cardiac and ocular function. No cure exists, but supportive care can improve quality of life.

Prognosis and Follow-Up

The condition follows a progressive course, with life expectancy often reduced due to cardiac or neurological complications. Regular follow-up with cardiologists, neurologists, and endocrinologists is essential to monitor and address systemic manifestations. Early intervention for cardiac issues can improve outcomes.

Complications

• Complete heart block requiring pacemaker implantation
• Severe vision loss from retinopathy
• Respiratory failure from muscle weakness
• Endocrine disorders (e.g., diabetes, hypoparathyroidism)
• Neurological decline

Lifestyle & Prevention

While no prevention exists for sporadic mitochondrial deletions, regular medical monitoring can help manage complications. Patients should avoid medications that may worsen mitochondrial function (e.g., certain anesthetics) and maintain a balanced diet to support overall health.

When to Seek Professional Help

Seek immediate care for symptoms like syncope, chest pain, or sudden vision changes, which may indicate cardiac or ocular emergencies. Routine follow-up is recommended for ongoing management of systemic manifestations.

Tips for Medical Coders

Use this code for bilateral manifestations of Kearns-Sayre syndrome. Document the bilateral nature of ocular symptoms (ophthalmoplegia, retinopathy) and any associated systemic findings. Ensure clinical correlation with genetic testing or diagnostic results to support the diagnosis.