Marinesco–Sjögren syndrome is a multisystemic early onset disorder caused by mutations in the SIL1 (SIL1 Nucleotide Exchange Factor) gene, which encodes a nuclear exchange factor for the endoplasmic reticulum resident chaperone BiP (binding immunoglobulin protein) [26]. The gene discussed is SIL1; the disease is Marinesco-Sjogren syndrome.