Abstract: An I-CreI variant, wherein at least one of the two I-Cre1 monomers has at least two substitutions, one in each of the two functional subdomains of the LAGLIDADG core domain situated from positions 26 to 40 and 44 to 77 of I-CreI, said variant being able to cleave a DNA target sequence from the genome of a non-integrating virus, in particular herpes simplex virus (HSV) or Hepatitis B virus (HBV) for use in genome engineering and for in vivo and ex vivo (gene cell therapy) genome therapy as well as the treatment of a virus infection.

Abstract: The present invention relates to a method to treat a genetic disease in an individual caused by at least one frame shift or at least one non sense mutation in the human dystrophin gene comprising at least the step of bringing into contact at least one meganuclease enzyme, which recognizes and cuts a target site in the human dystrophin gene, with the genome of said individual under conditions wherein said at least one meganuclease recognizes and cleaves its target site in the human dystrophin gene. Said method applies also to a set of meganuclease enzymes, which each recognizes and cuts a different target site. The present invention also relates to a kit comprising, at least one meganuclease enzyme as defined above and medicament comprising said meganuclease.