Mitochondrial disorders are caused due to variants in genes located on the
mitochondrial DNA or the nuclear
DNA. Here, we report a case with
mitochondrial encephalopathy,
lactic acidosis, and
stroke-like episodes (
MELAS)/Leigh overlap syndrome due to variant m.13513G>A in ND5. A 60-month-old female with a congenital, complex, multisystem phenotype was diagnosed with
MELAS/Leigh overlap syndrome due to variant m.13513G>A in ND5. Brainstem involvement resulted in
dysphagia,
dysarthria, and
respiratory failure with recurrent episodes of
aspiration, respiratory insufficiency, desaturations, lack of respiratory drive,
hypercapnia, and
pneumonia. Treatment was symptomatic and included
non-invasive ventilation,
antibiotics, implantation of a percutaneous endoscopic
gastrostomy, anti-seizure drugs, anti-
dystonia medication, a cocktail of
vitamins and
antioxidants, and
analgesics. Despite these measures, the outcome was poor as the patient died at the age of 62 months after being discharged to home
palliative care. In summary, the m.13513G>A variant can manifest as
MELAS/Leigh overlap syndrome with
Leigh syndrome dominating. Because of brainstem involvement leading to respiratory dysfunction,
dysarthria, and
dysphagia, the outcome is poor, despite symptomatic measures.