It is rare but people in their s and I would still think that people think that a fairly young age  httpwwwmentalhealthcommagpmalzhtml  Onset in the most severe form associated with the new gene can appear as early as age   On from the original quoteAlzheimers disease which occur late in life  I would not consider  late in life nor would a lot of other people We are not living in medieval times because then  would be regarded as late in life  Cheers