A de novo triplication on 2q22.3 including the entire ZEB2 gene associated with global developmental delay, multiple congenital anomalies and behavioral abnormalities

Haiming Yuan, Lina Zhang, Mengfan Chen, Junping Zhu, Zhe Meng, Liyang Liang

Mowat-Wilson syndrome (MWS) is a genetic condition characterized by distinctive facial features, moderate to severe intellectual disability, developmental delay and multiple congenital anomalies. MWS is caused by heterozygous mutations or deletions of the ZEB2 gene located on chromosome 2q22.3. At present, over 190 cases with mutations and deletions involving the ZEB2 gene have been reported, but triplication or duplication of reciprocal region of Mowat-Wilson syndrome has never been reported. Here we report a 2-year-2-month-old boy carrying a de novo 2.9 Mb complex copy number gain at 2q22.3 involving triplication of ZEB2 gene. The boy is characterized by intrauterine growth retardation, hypotonia, cognitive impairment, multiple congenital anomalies and behavioral abnormalities. This case provides evidence that triplication of ZEB2 gene may be clinical significance and ZEB2 gene is likely to be a dosage sensitive gene.