This study will enrol individuals who have, or may have, Factor V Leiden or Prothrombin G20210A mutations, which are genetic changes linked to an increased risk of blood clots. Targeted genetic testing will be carried out, where appropriate, to confirm whether participants have one of these genetic variants. Those with a confirmed result will attend a site visit for basic health checks, including blood pressure measurements, ECG, and blood tests, to establish a baseline of their general health and help identify suitability for future related clinical trials.

The study also provides participants with the opportunity to learn more about clinical research and become familiar with the clinical trial unit and team. Participation lasts approximately 10 weeks and includes 1-2 site visits and a follow-up telephone call.

This study aims to engage people who have, or may have, Factor V Leiden or Prothrombin G20210A mutations, which are genetic changes that can increase the risk of blood clots such as stroke. The study will collect health information to establish a clinical baseline for each participant. This can later help identify which participants are more likely to be included in Factor V Leiden or Prothrombin G20210A-related clinical trials.

The study also helps participants understand what taking part in a clinical trial involves. It gives them the chance to visit the clinical trials unit and become familiar with the clinical team before deciding whether they would like to join future studies related to these conditions.

Targeted genetic testing will be used to confirm whether participants have Factor V Leiden or Prothrombin G20210A mutations. This is particularly helpful for people from groups where these genetic changes are suspected and may allow some participants to receive a formal diagnosis.

The study will take approximately 10 weeks for participants to complete, consisting of 1 to 2 visits and a follow-up telephone call. Participants will first attend a screening visit, where the study will be explained and written consent will be taken. Following the informed consent, a genetic test will be performed for participants who are suspected of having Factor V Leiden or Prothrombin G20210A mutations.

Participants with confirmed diagnosis will be invited to a Day 1 visit. At this visit, participants will undergo a series of basic clinical assessments, such as blood pressure, heart recordings (ECGs), and blood tests. These assessments will help to establish a clinical baseline of the participant's health. Participants will receive a guided tour of the clinical trial unit to become familiar with its setting and environment.

Participants may also be provided with a hard copy of a Participant Information Sheet/Informed Consent Form (PIS/ICF) of any future relevant clinical trial (provided this document has received approval from the REC). This will allow potential participants to take the information home for a thorough review and discussion with friends and family before potentially attending a screening appointment for any future trials. A follow-up telephone call with the Study Doctor will be conducted within 1 week after Day 1 to discuss the results of the clinical assessments, allow participants to ask any questions and arrange specialist referrals or follow-up from their GP if required to support the participant's ongoing care

Inclusion Criteria:

1. Male or female participants aged ≥ 18 years at the date of signing the Participant Information Sheet/Informed Consent Form (PIS/ICF).
2. Ability to provide written, personally signed, and dated informed consent in accordance with International Council for Harmonisation (ICH) Good Clinical Practice (GCP) Guidelines E6 (R3) (2025) and applicable regulations, before any study-specific procedures are performed.
3. Confirmed or suspected diagnosis of FVL or Prothrombin G20210A mutation via targeted genetic testing.

Exclusion Criteria:

1. Unwilling or unable to comply with the protocol-defined study assessments.
2. Any other significant disease or disorder that, in the opinion of the Principal Investigator (PI) or Sponsor, may either place the participant at risk from participation, or influence the clinical baseline.

Adult participants with known or suspected FVL or Prothrombin G20210A mutation

Sharing of personal data with other organisations is not planned.