In this study, we evaluated magnetization transfer ratio values in the brain white matter of siblings of multiple sclerosis (MS) patients and compared them to those obtained in sex- and age-matched normal controls. No statistically significant difference was found between the two groups for all the white matter areas studied (frontal and occipital lobes, centrum semiovale, periventricular white matter, internal capsule, genu and splenium of the corpus callosum).