CD38 and Fryns syndrome: However, the evidence that total B cells as well as memory CD38- B cells and memory CD27+ B cell frequencies were selectively increased in FRNS/SDNS compared to both healthy volunteers and SRNS patients under steroid treatment argues against an impact of steroids on memory B cell changes, suggesting, instead, a role of memory B cells in the pathogenesis of adult FRNS/SDNS.