A young child with recurrent episodes of headaches and vision loss: Diagnostic clues?

MELAS is a mitochondrial cytopathy, with maternal inheritance and variable phenotype expression and severity depending on the degree of heteroplasmy. It presents with waxing and waning symptoms, in form of recurrent migrainous headache, transient loss of sight, hemianopsia, transient ischemic attack, or stroke-like episodes, focal seizures and even periods of altered sensorium. Here we present an 8-year-old boy presented with recurrent episodes of migrainous headache associated with vomiting sometimes and recurrent episodes of loss of vision for the past one year. As many of these episodes were precipitated by some febrile illness, so the child was suspected to have neurotuberculosis outside, because of Mantoux positivity. His mother also had similar episodes of recurrent headache and ultimately succumbed to cerebrovascular accident. Mitochondrial genome sequencing revealed heteroplasmic missense variation in the MT-TL1 gene (chrM:3243A>G).