**1. Introduction**

Since March 2020, the dramatic outbreak of Corona Virus Disease 2019 (COVID-19) in Italy has changed our lifestyle as individuals, physicians, and patients. Despite the evidence of minor involvement of children [1], pediatric units also had to deal with healthcare crises.

As a Referral Centre for Inborn Errors of Metabolism (IEM), we had to face an unexpected restriction concerning daily normal activity with lowering of programmed admissions for diagnosis and follow-up visits. Our concern was especially directed to those patients with lysosomal storage disorders (LSDs), which are rare, chronic, progressive, multisystem diseases associated with serious medical issues, physical disability, and psychological burden [2]. In the last decade, some of the LSDs became treatable by pharmacological therapy, such as intravenous (iv) enzyme replacement therapy (ERT) and oral substrate reduction therapy (SRT), or chaperones. During the COVID-19 alert, patients with LSDs, under regular treatment with ERT, failed their usual compliant behavior, missing scheduled infusions. Based on the feeling that our patients were experiencing profound distress, we designed a structured interview [3,4] with the aim to evaluate how, and to which extent, the COVID-19

pandemic was changing our patients' behavior and feelings about their chronic disease, the impact on therapies, and their future expectations. We emphasize the importance to investigate attitudes and behavior with respect to health treatment, especially among people with rare diseases, such as patients with LSD. They represent a group with increased vulnerabilities to COVID-19; thus, we felt the need to attempt any possible solution that would let them maintain treatment protocols and minimize disease progression.
