Late-onset Leigh syndrome without delayed development in China: A case report

Area of Science:

• Mitochondrial genetics
• Pediatric neurology

Background:

• Leigh syndrome (LS) is a common, typically early-onset mitochondrial disease.
• LS usually presents with developmental delay, but late-onset forms are rare.

Observation:

• A 12-year-old boy experienced a rare, late-onset, fulminant Leigh syndrome.
• He presented with ptosis and somnolence, without prior developmental delay.
• Brain MRI showed white matter, basal ganglia, and brain stem lesions.

Findings:

• Genetic analysis revealed a homoplasmic m.9176T>C mutation, confirming Leigh syndrome.
• The patient's condition rapidly deteriorated, leading to death within two months.

Implications:

• This case underscores the phenotypic variability of Leigh syndrome.
• It highlights the importance of considering LS in older children with unexplained neurological decline.