Test Details: Neuropathy ataxia retinitis pigmentosa (NARP) syndrome is characterized by sensory neuropathy, developmental delay and pigmentary retinopathy. It is a rare inherited disorder associated with T8993G mutation in mitochondrial DNA (mtDNA). PCR is used in diagnostic testing for NARP by mutation analysis of mitochondrial ATP6 gene followed by direct nucleotide sequencing of the PCR products.