This study aims to evaluate the Belzutifan's efficacy, drug safety, disease course, and the health-economic impact of the treatment to Von Hippel-Lindau (VHL) syndrome.

Adult patients diagnosed with VHL syndrome who choose to use belzutifan for their treatment will be identified and invited to participate in this registry. Clinical data, laboratory tests, imaging results and QOLs will be collected from subjects at baseline, every 3 months for the first year, then every 6 months until month 36 or cessation of the medication, whichever occurs first.

Inclusion Criteria:

• Adult patients (age 18 or above) with confirmed VHL-spectrum disease through clinical and/or genetic diagnosis.
• The patient decided to use Belzutifan for their treatment.

Exclusion Criteria:

• Tumour requiring immediate resection.
• Pregnancy or unwillingness to use contraception if of childbearing potential.
• Uncontrolled comorbidities (e.g., active infection, severe cardiopulmonary disease).

Adult patients diagnosed with VHL syndrome who choose to use belzutifan for their treatment