Cell lineage involvement of the COX I mutation in patient no. 1. Total DNA was extracted from different types of cells: Bm, bone marrow; Bl, peripheral blood; Plt, platelets; G, erythrocyte/granulocyte pellet; T, T lymphocytes; B, B lymphocytes; Mu, buccal mucosa cells; lane 8, DNA size marker; M, peripheral blood from the mother of patient no. 1; D1 and D2, peripheral blood from the first and second daughter of patient no. 1. See text for explanation of the restriction pattern.