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. Speech is typically limited to a few words or is absent, with relative preservation of receptive language skills. Growth restriction with microcephaly and seizure disorder are also common. Most affected people have a happy demeanor and a wide-based gait that can sometimes be confused with
Angelman syndrome. The diagnosis of MWS confirmed by demonstrating a pathogenic variant (mutation) in the
ZEB2 gene by molecular
genetic testing. ==Treatment==