Alpers' disease is a mitochondrially inherited disease with symptoms that include seizures, dementia, blindness, liver dysfunction, and cerebral degeneration. The pedigree below shows the presence of Alpers' disease in three generations. Individual 4had one daughter and two sons, and individual 6 had two daughters and one son.
Which of the individuals indicated below are affected by Alpers' disease? Place the correct symbols on the pedigree showing affected and unaffected individuals.