PSEN1 and Alzheimer disease: PSEN1DE9 carriers were 48-year-old male with AD diagnosis and a presymptomatic 47-year-old female and iPSC-lines were edited by CRISPR/Cas9 system to create isogenic control lines where mutation comprising 4.6-kb deletion in the exon 9 of the PSEN1 gene [28] was corrected [23].