A patient with vertebral, cognitive and behavioural abnormalities and a de novo deletion of NRXN1alpha.

The authors report a patient with mild mental retardation, autistic features, multiple vertebral malformations, and an unusual facial appearance who carries a de novo submicroscopic deletion of chromosome 2p16.3. The patient's deletion is approximately 320 kb in size and includes only the part of the NRXN1 gene that codes for the neurexin1alpha promoter and initial coding exons. The more downstream neurexin1beta promoter and the region surrounding it are intact. Neurexin1beta has been associated with autism in several recent studies, but this is the first reported patient with loss of only neurexin1alpha and not of neurexin1beta. These findings suggest that neurexin1alpha function in correct dosage is necessary for normal neurological development.