Fig. 1.

Information about each variant of interest in NRXN1. a Diagram of NRXN1α and NRXN1β protein (NCBI reference sequences NP_004792 and NP_620072, respectively) with three novel variants detected in this study. NRXN1α contains six LNS domains with three interspersed epidermal growth factor-like (EGF) repeats, followed by an O-linked sugar modification sequence, a short cysteine-loop domain, a transmembrane region, and a cytoplasmic sequence of 55–56 residues. NRXN1β is composed of a unique N-terminal β-neurexin-specific sequence that splices into the NRXN1α sequence N-terminal of its LNS6 domain. Localization of the protein domain is based on the Human Protein Reference Database. LNS, laminin/neurexin/sex hormone binding globulin domain; TM, transmembrane; p, protein. b Multiple alignments of amino acid sequences for eight NRXN1α vertebrate homologs