This trial aims to implement and compare an evidence- and theory-based intervention strategy (IGNITE-TX Intervention) to support probands and their ARRs in family communication, informed decision-making, and navigation to CGT with standard of care, free genetic testing/counseling, and intervention with free genetic testing/counseling.

Primary Objectives:

1. Determine the impact of IGNITE-TX on the uptake of cascade genetic testing (CGT) in at-risk relatives (ARRs) at 6 months.
2. Use a mixed methods approach, guided by the NIMHD framework, to evaluate the impact of IGNITE-TX on informational, social, and emotional support outcomes within families at 6 months.
3. Employ formative and process evaluations and stakeholder engagement to guide IGNITE-TX implementation and dissemination through the RE-AIM QuEST framework.

Secondary Objective:

1. Analyze the correlation of CGT completion rates within families to understand the influence of familial relationships on genetic testing uptake.

Exploratory Objective:

Evaluate the effectiveness of social media as a mechanism to drive outreach, recruitment, and engagement with the IGNITE-TX intervention.

Inclusion Criteria:

Probands:

1. 18 years of age or older
2. Speaks and reads English or Spanish
3. Resides in the United States
4. Has a pathogenic or suspected pathogenic variant in BRCA1, BRCA2, MLH1, MSH2/EPCAM, MSH6, or PMS2*
5. Has access to the internet or phone and can send and receive email and/or text messages at a US telephone number.
6. Attests to have at least one at-risk relative who meets inclusion criteria for first-degree relative *For cancer patients who are unaware of their mutation status, we will share existing local and national genetics resources, like those provided in the usual care family letter.

At-Risk Relatives (ARR):

1. 18 years of age or older
2. Speaks and reads English or Spanish
3. Resides in the United States
4. Has a first or second degree relative who has a deleterious/suspected deleterious HBOC or LS variant present
5. Has access to internet or phone and can send and receive email and/or text messages at a US telephone number

Exclusion Criteria:

Probands:

1. Has no eligible at-risk relatives (ARRs) or is unable/unwilling to provide their contact information
2. Has negative germline genetic testing or only variant of uncertain significance
3. Unwilling or unable to provide consent

At-Risk Relatives (ARR):

1. Unwilling or unable to provide consent
2. Reports no known HBOC or LS variant within the family
3. Has already been tested for the variant identified in the proband
4. Already listed as an ARR for another proband