9q34.11 Microduplications Encompassing SET Gene Are Associated With Neurodevelopmental Disorder and Recurrent Dysmorphisms

: Copy number variants (CNV) are a major cause of neurodevelopmental disorders. Novel CNV syndromes may still be unrecognized. We report a 9q34.11 microduplication syndrome characterized by neurodevelopmental impairment and recurrent facial anomalies. Following the identification of a de novo 9q34.11 microduplication involving the SET and SPTAN1 genes in an 11-year-old girl with speech delay, intellectual disability, and behavioral abnormalities, we identified 13 additional patients with overlapping duplications. Besides the neurodevelopmental disorder, clinical features observed among affected individuals included recurrent dysmorphic features, such as midface hypoplasia and thin lips. The minimal region of overlap among these cases contained the SET gene, suggesting that its triplosensitivity may play a role in the observed phenotypes.