This is a single-centre, cross-sectional observational study aiming to assess the psychological burden, quality of life, and perceived barriers to care in patients with von Hippel-Lindau syndrome (VHL). Data will be collected through an anonymous online questionnaire, specifically designed for the study and administered via Google Forms.

This is a single-centre, cross-sectional observational study designed to assess the psychological burden and health-related quality of life in individuals with von Hippel-Lindau (VHL) syndrome, and to explore perceived barriers to healthcare access and the perceived adequacy of multidisciplinary care.

The hypothesis underlying this study is that individuals affected by VHL experience a substantial psychological burden and face variable access to appropriate care pathways, which may differ based on demographic or clinical factors.

The study will involve a single group of participants (n ≈ 200). No control group or randomization is foreseen. The study duration is estimated at 10 years, including data collection and analysis.

Each participant will be involved once, with a single data collection session (approx. 25-30 minutes) through the study-specific questionnaire "VHL: Accesso alle cure e vita quotidiana". The questionnaire, administered in Italian via the Google Forms platform, is not part of routine clinical practice and is administered exclusively for research purposes.

Inclusion Criteria:

• Age ≥18 years
• Genetically confirmed diagnosis of von Hippel- Lindau syndrome

Exclusion Criteria:

• Inability to understand or complete the questionnaire, either independently or with assistance

Adult subjects (≥18 years) with confirmed diagnosis of von Hippel - Lindau syndrome