RECQL4 and Bloom syndrome: Notably, although it has been suggested that the function of RECQL1 may be redundant with other RecQ helicases such as BLM (30), the individuals affected by the RECQL1 p.A459S mutation exhibit a clinical phenotype distinct from that of BS, WS, and the 3 RECQL4-associated disorders, suggesting that RECQL1 is not redundant with WRN, BLM, or RECQL4 and has unique functions during human development.