21q21 deletion involving NCAM2: report of 3 cases with neurodevelopmental disorders.

Here we report three patients affected with neurodevelopmental disorders and harbouring 21q21 deletions involving NCAM2 gene. NCAM (Neural Cell Adhesion Molecule) proteins are involved in axonal migration, synaptic formation and plasticity. Poor axonal growth and fasciculation is observed in animal models deficient for NCAM2. Moreover, this gene has been proposed as a candidate for autism, based on genome-wide association studies. In this report, we provide a comprehensive molecular and phenotypical characterisation of three deletion cases giving additional clues for the involvement of NCAM2 in neurodevelopment.