ABSTRACT
Mitochondrial diseases (MiDs) exhibit significant clinical and genetic heterogeneity. Mitochondria are highly dynamic organelles that are the major contributor of ATP, via oxidative phosphorylation (OXPHOS). The disorders may develop at any age, with isolated or multiple systems’ involvement, and in any pattern of inheritance. Defects in the mitochondrial respiratory chain impair energy production and almost invariably involve skeletal muscle and peripheral nerves, causing exercise intolerance, cramps, recurrent myoglobinuria, or fixed weakness, which often affects extra ocular muscles and results in droopy eyelids (ptosis), progressive external ophthalmoplegia, peripheral ataxia and peripheral polyneuropathy.
This review describes the main neuromuscular symptomatology through different syndromes. We want to highlight the importance on searching for the “clue clinical signs” associated to inheritance pattern as key elements to guide the complex diagnosis process and genetic studies in MiDs.
