Siblings with cystic leukoencephalopathy and megalencephaly.

Cystic leukoencephalopathy with megalencephaly is a newly described entity with mild clinical involvement. Patients suffer from developmental problems and seizures in childhood. Progression is gradual into adulthood. Typical magnetic resonance imaging findings include subcortical cysts and diffuse leukoencephalopathy. The etiology is unknown with possibly autosomal-recessive inheritance. We present two pairs of siblings with this disease and emphasize the characteristic and variable patterns even within the same family.