| Modification Notes |
The SACS gene encodes Sacsin, a protein that plays an important role in chaperone-mediated protein folding and shows predominant expression in the central nervous system. Sacsin expression is also detected in skeletal muscle and pancreas tissues. Sacsin contains 7 nuclear localization signals, 3 coiled-coils, and 2 leucine zipper motifs, in addition to the DnaJ motif and the hydrophobic domain contained within Sacsin’s C-terminal region. Defects in the SACS gene can cause autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS), an early onset neurodegenerative disease characterized by reduced motor-nerve velocity, absent sensory-nerve conduction and hypermyelination of retinal-nerve fibers. ARSACS is highly prevalent in the Charlevoix-Saguenay-Lac-Saint-Jean region of Quebec. |