A new syndrome of nonprogressive encephalopathy with normo- or microcephaly and early onset of psychomotor impairment is described in 15 children, in a report from the University of Gottingen and other centers in Europe and the US. Clinical findings include patients of Turkish origin; consanguinity of parents in 5; 2 patients siblings and 2 first cousins; age at onset birth to 18 months; microcephaly in 9 and normocephaly in 6; impaired motor and mental development; epilepsy in 8; spasticity in 12; hearing impairment in 5; normal peripheral nerves; course stable or slowly progressive. Tests for metabolic and infectious disease were negative. MRI findings included supratentorial white matter lesions with a high signal on T2 weighted images involving mainly periventricular regions, sparing of central white matter and cerebellar white matter, cystic lesions in anterotemporal lobes not connected to the ventricles, pericystic abnormal myelination on FLAIR-weighted images, enlarged temporal horn, and no involvement of gray matter. The cause is unknown, but an autosomal recessive inheritance is suspected and is under investigation. 
COMMENT. The authors distinguish this autosomal recessive disease from a previously described cystic leukoencephalopathy with megalencephaly (MLC), caused by a mutation of MLC1 gene. (Van der Knapp et al, 1995; Progress in Pediatric Neurology III, 1997;p557). In MLC, the MRI showed supratentorial white matter swelling and subcortical cysts, which contrasted with a mild clinical course.