SMN2 and proximal spinal muscular atrophy: Furthermore,although SMA is widely known as a spinal motor neuron disease, recent evidence hassuggested it may be considered a multi-organ disease.3 SMN1 is expressed in the brain and rare cases of SMA with no SMN2 (SMAtype 0) develop white matter and hippocampus atrophy.3 These patients also show thalamus and basal ganglia hyperintensity onresonance magnetic imaging.3 Therefore, thesevere reduction in SMN protein levels might lead to progressive encephalicdysfunction and degeneration.3