[4] The clinical manifestations present at birth are generalized hypotonia, muscle weakness, developmental delay with intellectual disability and occasional seizures.

Half of all children with WWS are born with encephalocele, which is a gap in the skull that will not seal.

The meninges of the brain protrude through this gap due to the neural tube failing to close during development.

[8] Laboratory investigations usually show elevated creatine kinase, myopathic/dystrophic muscle pathology and altered α-dystroglycan.

Prenatal ultrasound may be helpful for diagnosis in families where the molecular defect is unknown.