What are the symptoms? The major features of MWS are: moderate-to-severe learning disabilitymicrocephalyseizures (see entry Epilepsy)constipation (Hirschsprung’s disease is only present in a minority of patients). Typical facial features that include: deep-set, widely-spaced eyesthick eyebrowscharacteristic ear shape with a turned-up ear lobebroad nasal tip and short philtrum (the vertical central groove from the nose to the upper lip)small open mouth with a highly arched palateprominent chin. Other features that have been observed in individuals with MWS include: growth, and developmental delay – speech can be delayed or absentfailure to thrive in early lifecongenital heart disease (see entry Heart Defects)genitourinary anomalieseye anomalieswhite patches on the skinagenesis of the corpus callosum, which is visible on a magnetic resonance imaging (MRI) scan. A number of behavioural features have been seen in MWS, these include: sociable, happy dispositiondisrupted sleep patterntooth grinding and repetitive movements. What are the causes? Almost all patients with MWS have a mutation or a deletion of the ZEB2 gene (previously known as the ZFHX1B or SIP1 gene) on chromosome 2q22. Some patients have a chromosome rearrangement which interferes with the function of this gene. How is it diagnosed? Diagnosis of the Syndrome is made by recognition of the clinical features and identification of a ZFHX1B gene change. Diagnosis of the syndrome has been made on clinical grounds alone in a number of individuals without the gene mutation. How is it treated? MWS syndrome cannot be cured. Treatment is symptomatic (addressing the symptoms an individual experiences as part of the syndrome) and aimed at maintaining or improving quality of life. Inheritance patterns and prenatal diagnosis Inheritance patternsMWS is usually a sporadic disorder although there are rare families where two children have been affected. Genetic advice or counselling is therefore recommended for families. Prenatal diagnosisThis may be possible in families with an affected child where a genetic change of ZEB2 has previously been identified in which a case of MWS exists. Is there support? Families can use Contact’s freephone helpline for advice, information and, where possible, links to other families. To meet other families with disabled children, join Contact’s closed (private) Facebook group.