HSPA5 and Marinesco-Sjogren syndrome: Meanwhile, disruption of the SIL1-HSPA5 system may prevent synthesis and ER quality control not only of reelin but also of other proteins, since the knock-in mouse has additional phenotypes not observed in reelin-deficient reeler mouse, such as reduction in the whole brain size, which is a frequent symptom of MSS (Mimura et al, 2008).