Clinical and genetic analysis of Chinese patients with Leigh syndrome caused by biallelic loss-of-function variants of the NDUFAF6 gene

Leigh syndrome (LS) is the most common pediatric mitochondrial disorder, typically presenting in infancy with developmental regression, neurological dysfunction, and characteristic brain MRI lesions. It is linked to over 110 genes affecting cellular energy production, making it highly genetically heterogeneous, with complex I deficiency being the most frequent cause. Biallelic mutations in NDUFAF6—a key assembly factor of complex I—cause autosomal recessive Leigh syndrome, specifically NDUFAF6-r