Autosomal dominant Alzheimer’s disease (ADAD) accounts for approximately 1% of all Alzheimer’s disease (AD) cases [2] and is usually caused by mutations in one of three known genes, namely PSEN1 (OMIM 104311), APP (OMIM 104760), and PSEN2 (OMIM 1600759). The gene discussed is PSEN2; the disease is Alzheimer disease.