Bernard-Soulier syndrome (BSS; MIM #231200) is a rare autosomal-recessive bleeding disorder caused by biallelic variants in the GP1BA, GP1BB, and GP9 genes that encode the subunits GPIbα, GPIbβ, and GPIX, respectively, of the GPIb-IX receptor complex [1]. Here, GP1BB is linked to Bernard-Soulier syndrome.