18q-syndrome: brain MRI shows poor differentiation of gray and white matter on T2-weighted images.

Purpose: To study brain MRI findings in patients with 18q- syndrome and to correlate these findings with the results of the molecular breakpoint analysis.

Materials And Methods: Brain MR images of 17 patients with 18q- syndrome were evaluated. Segregation analysis was performed with 15 microsatellite markers to determine the deletion breakpoints and whether the deletion included the myelin basic protein (MBP) gene.