[6] The disorder is expressed in an autosomal dominant fashion and may result from a de novo loss of function mutation or total deletion of the ZEB2 gene located on chromosome 2q22.

[7] Mowat–Wilson syndrome (MWS) can be diagnosed clinically on the basis of moderate to severe intellectual disability in the presence of characteristic facial features (widely spaced eyes, broad eyebrows with a medial flare, low-hanging columella, prominent or pointed chin, open-mouth expression, and uplifted earlobes with a central depression — coined as orecchiette ears given their resemblance to the pasta).

Other clinical features can include congenital heart defects, Hirschsprung disease or chronic constipation, genitourinary anomalies (particularly hypospadias in males), and hypogenesis or agenesis of the corpus callosum.

The diagnosis of MWS confirmed by demonstrating a pathogenic variant (mutation) in the ZEB2 gene by molecular genetic testing.

Affected individuals should see a pediatrician or adult physician at least annually to monitor growth, development, seizures and general health and well-being.