From the Research
NARP (Neuropathy, Ataxia, and Retinitis Pigmentosa) syndrome typically presents in childhood or early adulthood, with most patients developing symptoms between early childhood and young adulthood. The age of presentation can vary widely, with many cases becoming apparent in the first decade of life 1. The clinical manifestations often begin with developmental delay, learning disabilities, or seizures in childhood, followed by progressive symptoms including peripheral neuropathy, ataxia (loss of coordination), and retinitis pigmentosa (vision loss) 2. Some patients may present with more severe manifestations in infancy, including failure to thrive, while others might have milder symptoms that don't become apparent until adulthood 3. The variability in age of presentation relates to heteroplasmy (the proportion of mutated mitochondrial DNA), with higher mutation loads generally correlating with earlier and more severe disease 4. Key points to consider in the diagnosis and management of NARP syndrome include:
- Maternal inheritance patterns are typical, with affected mothers transmitting the mutation to all their children, though the severity can differ significantly even within families due to varying levels of heteroplasmy 5
- A genetic etiology should be established to confirm the diagnosis, and molecular-genetic methods are usually used for this purpose 1
- Symptomatic treatment can improve patients' quality of life, and a correct diagnosis is the prerequisite for genetic counseling and personalized treatment 2