Anti-Ro52 autoantibodies, shared by both conditions, may blur early diagnostic attribution, particularly when glandular symptoms precede myositis-spectrum features.<h4>Objectives</h4>To characterize the clinical phenotype, serological profile, and disease trajectory of patients fulfilling classification criteria for both SjD and ASyS.<h4>Methods</h4>We conducted a multicentre retrospective study (2018-2025) across three Italian referral centres, including patients meeting both the 2016 ACR/EULAR SjD criteria and the Connor's/provisional CLASS classification criteria for ASyS. The gene discussed is TRIM21; the disease is myositis disease.