A Diagnosis to Consider in Intellectual Disability: Mowat-Wilson Syndrome.

Mowat-Wilson syndrome is a multiple congenital anomaly and intellectual disability syndrome characterized by a unique face and various other structural and functional anomalies. The condition is caused by de novo heterozygous mutations or deletions in ZEB2 gene located at 2q22. ZEB2 encodes Sip1 protein, which acts during central nervous system development as an important transcription factor. Herein, we report on 3 novel mutations in 6 patients with the syndrome, with an overview of corresponding clinical findings. Growth retardation and Hirschsprung disease were less common in the present cohort. One patient with a novel mutation p.Y489X had no associated anomalies except the characteristic facial and neurobehavioral phenotype. Reporting new patients with novel mutations would contribute to better delineation of the syndrome and would help clinicians establish formal diagnostic criteria and genotype-phenotype correlations.