790 Kb microduplication in chromosome band 17p13.1 associated with intellectual disability, afebrile seizures, dysmorphic features, diabetes, and hypothyroidism.

We report a patient with a moderate mental retardation, afebrile seizure, mild dysmorphic features and type 2 diabetes mellitus with mild obesity and metabolic syndrome. Array-CGH analysis revealed a de novo 790-830 kb duplication on chromosome 17p13.1, not reported so far. Among the approximately 50 genes involved in the rearrangement, neuroligin 2 (NLGN2) and ephrin B3 (EFNB3) are candidates for the mental retardation phenotype. NLGN2 may therefore be a novel candidate gene for mental retardation or autistic spectrum disorder, joining other members of the neurexin/neuroligin network. Moreover, GLUT4, a member of the solute carrier family 2, may play a role in the patient's type 2 diabetes.