No preparation for a family letter is necessary before a visit to a genetic counselor. But when you are planning an appointment, you might think about what you want your letter to include. The counselor can customize a message to your family’s concerns. If you have a relative planning an appointment, help them consider what to include in their own letter.

For example, if you know which side of the family carries a mutation, the letter can name a grandparent who had the disease to clarify how the variant has been inherited.

The geographic locations of family members can also be useful. If the letter will go to a relative in Kansas City, it can include referral forms for genetic counselors in that area.

Do you anticipate confusion in your family? Mention this to your genetic counselor, who can address those misconceptions in the letter. Maybe your brother only has sons and doesn't know that a gene variant associated with breast cancer applies to them. The letter could explain that men can still inherit and pass on the variant. If you’ve already shown your letter to family members, what questions did they have after reading it? Share those questions with relatives who are getting ready for genetic testing. Your relatives can ask their own counselors to discuss those specific concerns in family letters.

If you’ve already shared your letter with your closest family members, consider giving it to other relatives. Generally, the letter is beneficial for parents, children, siblings, aunts, uncles and first cousins. If you know which side of the family the mutation comes from, focus on that side.

Most people don’t share the letter with more distant relatives because they can’t identify which second cousins are most at risk and might benefit. However, if you’ve learned which great-grandparent (or other relatives further back) had the mutation, you may be able to reach out to distant relatives.

Also consider who may be eligible for genetic testing. If you got tested because of your grandmother’s disease, your cousins with the same grandmother could have inherited the mutation. A family letter could alert those cousins that they could be eligible for testing, too—even if your own results are negative.

From this group, think about who you can reasonably contact in person, through email or over social media. If you aren’t in a position to give the letter personally to a certain individual, ask yourself if an intermediary in the family could pass on the letter.

In some situations, it may make sense to resend a letter to a relative who has not been tested after a year or more has passed. Perhaps your relative did not receive the first letter, or they received it at a time when they were not in a position to act. They could be ready to get tested but don’t have the information and are hesitant to ask you. Consider whether the time is right for a follow up, and be respectful of decisions when people make up their minds not to be tested.

It’s important to add your test results as an attachment to the letter. The report should include the date of testing, the specific test that was performed and the exact variant in the family. Your relatives should show this report to their health care providers to make sure they get the right genetic testing. If you’re uncomfortable sharing personal information, it’s fine to black out your name and other private details on the report.

You may choose to include a note to introduce the letter—or, if you are resending a letter, to tell your relative why you are sending it again. Don’t try to interpret the results. Simply let your relatives know that you are sending the letter because you think they might want to know what’s going on.

Send the letter in a way that fits how you usually communicate. In some families, emailing to a group works. You could distribute photocopies at a family reunion or post a message on social media—wherever ties exist in your family.

For other families, large-scale distribution isn’t possible. In that case, send the letter to those individuals you communicate with, using whatever method feels most comfortable for each person. To reach as many people as possible, recruit an ally in your family to help. Many families have one member who is in touch with everyone or does genealogy work. If this is not you, enlist this person.

When more than one person in your family has received letters, work as a team. Discuss how to share multiple letters. Maybe you realize that one letter has information more appropriate to a certain relative. Maybe you decide that everyone should share with the relatives they are closest to. Whenever a new relative visits a genetic counselor and receives a letter, they have the opportunity to send that additional letter to other family members who have not yet been tested.

Follow-up discussions can help relatives feel more comfortable about getting genetic testing, but the conversation doesn't have to continue if that doesn’t make sense for you and your family. Spread the letter in the spirit of sharing information, not convincing anyone to get genetic testing.

“That can be really hard,” Lang said. “Some of us feel that responsibility because we love our relatives and because we want them to be healthy.” Expect family members to have different responses. Not everyone feels the same way about genetic testing. Some may immediately get tested. Others may save the information for later or not want to think about it. All reactions are valid.

“Respect people’s choices,” Lang said. “Don’t assume everybody’s going to act the way you did when you were brought the option of genetic testing. And that’s okay. You’ve done your part by giving them the information.”