45% of pts with #MAS and 62% of pts with #secondaryHLH carry a heterozygous variant of a gene generally associated with #primaryHLH.  Having multiple variants assoc w worse and recurrent MAS or HLH. Abstract 2014 Drs. Passarelli and Bracaglia #ACR18 @RheumNow0 https://t.co/t0AGzQ8c7r