The pedigree and cranial MR images. DNA samples subjected to SNP genotyping are indicated by * on the pedigree, and those for variant testing are indicated by +. POLR1A and OSBPL11 variant genotypes are given. MR images of the brothers revealed enlarged ventricles, cortical sulci and subarachnoid spaces indicative of cerebral atrophy, diffuse hyperintense involvement of periventricular white matter extending to subcortical white matter, atrophy of the cerebellar hemispheres and the vermis, and thin corpus callosum. Brother 2 has additionally a subarachnoid cyst in the left posterior fossa. The sisters have normal MRI findings. Parents have normal white matter and very mild cerebral atrophy. (a) Axial T2 weighted. (b) Coronal T2 weighted. (c) Sagittal T1 weighted.