DNA was extracted from 500ul of saliva with the MaxwellRSC Stabilized Saliva DNA kit (Promega) according to the manufacturers instruction. At the end of the automated extraction, DNA was eluted in 60 L of water. The DNA quantification was performed with Qubit fluorometer (Qubit DNA HS Assay Kit; Invitrogen).  Sequencing libraries were prepared starting from 24ng of DNA using the Illumina DNA Prep, (M) Tagmentation kit (Illumina), following the manufacturers guidelines. The library pool was subjected to a cleaning step with 0.7x Agencourt AMPure XP beads. Samples were sequenced on a NovaSeq 6000 flow cells (Illumina) at the IIGM sequencing facility.