NARP Syndrome: Causes, Symptoms, Diagnosis, Treatment
Last reviewed: 23.04.2024
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[Causes and pathogenesis of NARP syndrome
At the heart of the disease is a point mutation at the 8993 mtDNA locus, which belongs to the class of mutation mutations, when leucine is replaced by arginine in the subunit of the sixth mitochondrial ATPase. Often a correlation is revealed between the severity of clinical manifestations of the disease and the number of abnormal mtDNA (the level of heteroplasmy).
Symptoms of NARP Syndrome
Clinical signs include the main symptoms: neuropathy, ataxia, retinitis pigmentosa. Often, children are observed a delay in neuropsychic development, spasticity, progressive dementia. However, the time of manifestation of the disease varies significantly (early and late debut). The severity ranges from malignant to benign forms. The course is progressive.
Diagnosis of NARP Syndrome
According to laboratory studies, lactate acidosis is often found, but it may not be. In the morphological study of muscles, sometimes there is a phenomenon of "torn" red fibers.
Differential diagnosis is performed with conditions accompanied by ataxia and pigment retinitis (olivopontocerebellar degenerations, Refsum's disease, abetalipoproteinemia).
How to examine?
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