The present invention provides polypeptide and polynucleotide sequences for novel splice variants of the sodium and chloride-dependent glycine transporter type 1 (GlyT1). These polypeptides and polynucleotides are useful in the treatment and diagnosis of disorders such as neurological and psychiatric disorders including schizophrenia. The invention also provides antibodies directed specifically against these novel polypeptides, and kits comprising the herein-described polynucleotides, polypeptides, and/or antibodies.