The GAA trinucleotide repeats in the FXN gene were analyzed by triplet repeat-primed PCR (TP-PCR) in 122 unrelated hereditary ataxia (HA) and 114 unrelated hereditary spastic paraplegia (HSP) patients.
Autosomal recessive ataxia of Charlevoix-Saguenay, late-onset Friedreich ataxia, and hereditary spastic paraplegia type 7 are examples of genetic diseases with such a prominent spastic-ataxic syndrome as the clinical hallmark.
Moreover, mitochondrial dysfunction plays an important role in the pathophysiology of several well established nuclear genetic disorders, such as dominant optic atrophy (mutations in OPA1), Friedreich's ataxia (FRDA), hereditary spastic paraplegia (SPG7), and Wilson's disease (ATP7B).
This survey reports such an analysis for 15 missense mutations, one insertion and three deletions involved in Leber's hereditary optic neuropathy, Leigh syndrome, mitochondrial neurogastrointestinal encephalomyopathy, Mohr-Tranebjaerg syndrome, iron-storage disorders related to Friedreich's ataxia, and hereditary spastic paraplegia.
Recent evidence shows that nuclear gene defects affecting mitochondrial function have a role in the pathogenesis of Friedreich's ataxia, Wilson's disease and hereditary spastic paraplegia.