Involvement of Mitochondrial Dysfunction in Syndrome.

(Forkhead box g1) syndrome is a neurodevelopmental disorder caused by a defective transcription factor, FOXG1, important for normal brain development and function. As syndrome and mitochondrial disorders have shared symptoms and FOXG1 regulates mitochondrial function, we investigated whether defective FOXG1 leads to mitochondrial dysfunction in five individuals with variants compared to controls ( = 6). We observed a significant decrease in mitochondrial content and adenosine triphosphate (ATP) levels and morphological changes in mitochondrial network in the fibroblasts of affected individuals, indicating involvement of mitochondrial dysfunction in syndrome pathogenesis. Further investigations are warranted to elucidate how FOXG1 deficiency impairs mitochondrial homeostasis.