Recent studies have shown that Nrx and Nlg defects cause or worsen neurodegenerative diseases, and the expression levels of Nlg and Nrx are significantly downregulated in Alzheimer’s disease (Martinez-Mir et al., 2013; Sindi et al., 2014), which suggests that Nrx and Nlg are associated with the synaptic degeneration that occurs in Drosophila NMJ boutons. Here, NXN is linked to early-onset autosomal dominant Alzheimer disease.