NRXN1 deletions have also been associated with a variety of other conditions including schizophrenia [International Schizophrenia Consortium, 2008; Kirov et al., 2008; Vrijenhoek et al., 2008; Walsh et al., 2008; Need et al., 2009; Rujescu et al., 2009], nicotine dependence [Bierut et al., 2007; Nussbaum et al., 2008], and other physical manifestations such as vertebral anomalies [Zahir et al., 2008]. Here, NRXN1 is linked to nicotine dependence.