NLGN1 and early-onset autosomal dominant Alzheimer disease: Alterations in the postsynaptic cell-adhesion molecule Neuroligin-1 (NL1) and its trans-synaptic partner Neurexin-1 (Nxn1) are associated with neuropsychiatric disorders such as autism spectrum disorders (ASD; Szatmari et al., 2007; Kim et al., 2008a; Kirov et al., 2008, 2009; Marshall et al., 2008; Walsh et al., 2008; Yan et al., 2008; Zahir et al., 2008; Glessner et al., 2009; Gratacòs et al., 2009; Millson et al., 2012; An et al., 2014), and may also be involved in cognitive decline in the Alzheimer’s disease (Saura et al., 2011; Bie et al., 2014).