Walker-Warburg syndrome

Overview
Walker-Warburg syndrome is a rare form of autosomal recessive congenital muscular dystrophy associated with brain (lissencephaly, hydrocephalus, cerebellar malformations) and eye abnormalities. This condition has a worldwide distribution. The overall incidence is unknown but a survey in North-eastern Italy has reported an incidence rate of 1.2 per 100,000 live births. It is the most severe form of congenital muscular dystrophy with most children dying before the age of three years.

Presentation
The clinical manifestations present at birth are generalized hypotonia, muscle weakness, developmental delay with mental retardation and occasional seizures. The congenital muscular dystrophy is characterized by hypoglycosylation of α-dystroglycan.

Genetics
Several genes have been implicated in the etiology of Walker-Warburg syndrome, and others are as yet unknown. Several mutations were found in the protein O-Mannosyltransferase 1 and 2 genes, and one mutation was found in each of the fukutin and fukutin-related protein genes.

Diagnosis
Laboratory investigations usually show elevated creatine kinase, myopathic/dystrophic muscle pathology and altered α-dystroglycan. Antenatal diagnosis is possible in families with known mutations. Prenatal ultrasound may be helpful for diagnosis in families where the molecular defect is unknown.

Prognosis
No specific treatment is available. Management is only supportive and preventive.