Neuropathy, Ataxia, and Retinitis Pigmentosa (NARP) is a rare mitochondrial disease primarily affecting the nervous system and vision. Neurologic symptoms may include muscle weakness, loss of balance or coordination called ataxia, and loss of sensation or pain in the limbs called sensory neuropathy. Some affected individuals may experience vision loss caused by deterioration of the retina, called retinitis pigmentosa. Symptoms typically manifest in childhood or early adulthood and progress over time, but symptoms and their severity vary widely amongst affected individuals [1]. As NARP progresses, affected individuals have decreased quality of life and increased dependence on others due to symptoms such as blindness, loss of balance, and muscle weakness. Some patients may also have cognitive impairment, which may be progressive in some cases. The exact prevalence of NARP is unknown but is estimated to be 1-9 in 100,000 [2]. NARP can occur in people who have family members affected by other mitochondrial diseases, like Leigh Syndrome.
Neuropathy, Ataxia, and Retinitis Pigmentosa (NARP) is a rare mitochondrial disease primarily affecting the nervous system and vision. Neurologic symptoms may include muscle weakness, loss of balance or coordination called ataxia, and loss of sensation or pain in the limbs called sensory neuropathy. Some affected individuals may experience vision loss caused by deterioration of the retina, called retinitis pigmentosa. Symptoms typically manifest in childhood or early adulthood and progress over time, but symptoms and their severity vary widely amongst affected individuals [1]. As NARP progresses, affected individuals have decreased quality of life and increased dependence on others due to symptoms such as blindness, loss of balance, and muscle weakness. Some patients may also have cognitive impairment, which may be progressive in some cases. The exact prevalence of NARP is unknown but is estimated to be 1-9 in 100,000 [2]. NARP can occur in people who have family members affected by other mitochondrial diseases, like Leigh Syndrome.
NARP typically manifests in childhood with loss of muscle coordination, learning difficulties, and developmental delay. In early adulthood, vision loss and muscle weakness manifest [2, 5]. NARP progresses over time. Symptoms of NARP vary between affected individuals, but may include [1, 2, 5, 6, 7]:
- Learning difficulties
- Developmental delay
- Poor coordination called ataxia
- Muscle weakness
- Muscle spasms
- Loss of sensation in the limbs called peripheral neuropathy, which may also cause discomfort
- Vision problems, including:
- Retinopathy, in which the retina deteriorates and causes vision loss; in NARP, the retinopathy is often accompanied by increased pigment in the eye, which can be called “salt and pepper retinopathy,” “pigmentary retinopathy” or “retinitis pigmentosa”. The retinopathy typically involves the part of the retina called the rods the most (“rod-cone retinal dystrophy”), which results in night blindness and impaired peripheral vision
- Weakness of eye muscles caused ophthalmoplegia
- Short stature
- Seizures/Epilepsy
- Depression, anxiety and other mood changes
- Headaches
- Loss of cognitive skills over time
- Sleep apnea
- Hearing loss
- Deterioration of the corticospinal tract, which controls the limbs and trunk
- Deterioration of brain cells in the part of the brain that control coordination (“cerebellar ataxia”)
- Speech problems called dysarthria
- Diabetes
To determine if your loved one has NARP, your healthcare provider may perform the following [2, 5]:
- Evaluate symptoms and family history
- Examination of the electrical activity of the retina called electroretinogram
- Examination of the electrical activity of muscles called electromyography
- Magnetic resonance imaging (MRI) to examine potential brain atrophy
- Molecular genetic testing
Like all mitochondrial diseases, there is currently no cure for NARP. Treatment is focused on supportive care to manage symptoms, including periodic follow ups with a multidisciplinary team of physicians. Other potential treatments include:
- Antioxidants
- Anticonvulsants for epileptic seizures
- Benzhexol, baclofen, tetrabenazine, and gabapentin for uncontrolled muscle contractions called dystonia
- Citrulline/arginine for low citrulline levels
- Visual aids for vision loss
- Hearing aids or cochlear implant for hearing loss
- Mobility aids such as wheelchairs
- Genetic counseling
- Mental health support
Affected individuals are recommended to use caution with anesthesia and other sedatives [2]. Caution is needed with dichloroacetate, which can worsen neuropathy. Routine surveillance for new or worsening symptoms is recommended [6].
Are there any clinical trials for NARP?
To see what trials you may qualify for, visit our Clinical Trials page – which also included a Clinical Trials Finder Tool. We also highly encourage you to join our patient registry, mitoSHARE, where we are actively recruiting NARP families.
- Get Support
Connect with our Support & Education Team online, via email at support@umdf.org or phone at (888) 900-6486.
- Check our clinical trials finder
Use our Clinical Trials Finder tool to see if you qualify for any clinical trials.
- Join our patient registry, mitoSHARE
We are actively recruiting NARP families to participate in our patient registry, mitoSHARE. Patient registries like mitoSHARE are an integral part in charting a course toward treatments and cures for NARP and other mitochondrial diseases. There are currently over 30 active mitochondrial disease clinical trials. Next generation patient registries like mitoSHARE are an integral part of expanding that number.
- Become an advocate
Ask your representatives to prioritize mitochondrial disease research and support via the UMDF Advocacy Center. We’ll send regular action items where you – and your friends and family – can let Congress know we need their support. Click here to sign up.
- Join the conversation online
– UMDF Social Media Support Groups: Facebook Support Group
– UMDF News & Updates: Facebook | Twitter | Instagram | YouTube
- Get involved
Join the fight by giving your voice, generosity, time, or energy. Click here to see how you can help.
UMDF is helping chart a path toward treatments and eventual cure of mitochondrial diseases like NARP through:
- Research & Funding: UMDF has provided more than $18 million in research funding to find treatments. UMDF advocacy has helped secure an additional $80 million in federal funding via the Department of Defense and National Institutes of Health.
- Data: Over two decades ago, UMDF pioneered patient registries for the mitochondrial disease community. Today, our next generation patient registry, mitoSHARE, is helping chart a path toward the treatment and eventual cure of mitochondrial diseases.
- Patient Support: Thousands of families just like you depend upon UMDF for support and education on diseases like NARP. Attendance at our support meetings annually tops 7,000, including disease specific support meetings for families.
- Clinician Support: To help educate clinicians on diseases like NARP, we feature monthly Bench to Bedside clinician seminars, host the annual Mitochondrial Medicine Symposium, support the Mitochondrial Care Network, and educate clinicians on our Mito U platform.
UMDF is here to help. Contact the Support Line at (888) 900-6486 weekdays from 8:00am to 5:00pm EST to connect with our Patient Concierge. Or, via email contact support@umdf.org.
- NIH Genetic and Rare Diseases Information Center, last updated May 2026. NARP syndrome.
- Orphanet, last updated May 2020. NARP syndrome.
- Ganetzky et al., 2019. MT-ATP6 Mitochondrial Disease Variants: Phenotypic and biochemical features analysis in 218 published cases and cohort of 14 new cases.
- UMDF, last updated April 2026. Leigh Syndrome.
- Angelini et al., 2017. NARP (Neuropathy, Ataxia, Retinitis Pigmentosa).
- Juaristi et al., 2018. Neuropathy, Ataxia, and Retinitis Pigmentosa Syndrome: A Multidisciplinary Diagnosis.
- Finsterer, 2023. Neuropathy, Ataxia, and Retinitis Pigmentosa Syndrome.