MERRF Syndrome

MERRF stands for Myoclonic Epilepsy with Ragged-Red Fibres, a rare mitochondrial disorder causing muscle jerks, seizures and progressive muscle weakness, with characteristic abnormal muscle fibres visible on biopsy.

MERRF is caused by mutations in mitochondrial DNA that impair energy production in cells, most commonly affecting a specific gene involved in mitochondrial protein synthesis. It is inherited through the maternal line.

Key symptoms include myoclonic jerks, generalised seizures, progressive muscle weakness and exercise intolerance, along with possible hearing loss, short stature, and coordination problems as the condition progresses.

MERRF is a progressive condition that can significantly affect quality of life and, in more severe cases, life expectancy, particularly where seizures are difficult to control or other organs such as the heart become involved.

Yes, it is inherited through mitochondrial DNA passed from mother to child, with severity varying between family members depending on the proportion of affected mitochondria in different tissues.

There is no cure, but seizure management with anticonvulsant medication, alongside physiotherapy and metabolic supplements such as coenzyme Q10, can help control symptoms and maintain function for longer.

Treatment centres on anticonvulsant medication for seizure control, physiotherapy for muscle weakness, and regular monitoring for associated problems like hearing loss or cardiac involvement, alongside supportive metabolic treatment.

See a neurologist promptly if unexplained muscle jerks, seizures or progressive weakness develop, particularly with a relevant family history. NHS referral can take time, while a private neurologist can typically arrange assessment within about two weeks.