Four-month-old infant with focal segmental glomerulosclerosis and mitochondrial DNA deletion. 
Mitochondrial cytopathies are a group of heterogeneous disorders characterized by multisystem involvement.  Renal involvement in mitochondrial cytopathies is usually manifested as tubular dysfunction owing to impaired energy metabolism; however, a few cases with glomerular changes have also been reported.  Herein we report the case of a 4-month-old Turkish girl with a mitochondrial DNA deletion and focal segmental glomerulosclerosis.