A community for anyone carrying, or wondering if they carry, an inherited cancer mutation. Plain-language education, real pathways to Canadian genetic counselling, and people who understand what a result actually feels like.

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1 in 200

Canadians is estimated to carry a BRCA1 or BRCA2 mutation (Women's College Hospital, The Screen Project)

50%

chance of inheriting a dominant cancer mutation like CDH1 or BRCA2 from an affected parent

Dozens

of genes beyond BRCA and CDH1 are now included on standard hereditary cancer testing panels

GCAA is a peer-led awareness and education initiative, not a medical or genetic counselling service. Nothing here is individual medical advice. Talk to your doctor or a certified genetic counsellor about your own risk.

What we do

Four ways in

Wherever you're starting from: newly tested, waiting on results, or just curious about your family tree, there's a page for that.

Our story

Why a family carrying both a CDH1 and a BRCA2 mutation decided to build this.

Learn the basics

Plain-language explainers on hereditary cancer syndromes, from BRCA to CDH1 to Lynch, and what your result actually means.

Get support

Canadian genetic counselling directories, hereditary cancer programs, and how to build your family history before an appointment.

Read real stories

We're just getting started collecting these, so there's nothing to read yet. Be one of the first to share yours.

Our story

Why we started GCAA

"Our family carries a CDH1 mutation, linked to hereditary diffuse gastric cancer, alongside BRCA2 mutations. We started GCAA because we know what it's like to sit with a genetic test result and have no idea what to do next."

Arya, Nina and Tina, GCAA co-founders

Two mutations. One family. A lot of appointments before we found our footing.

CDH1 and BRCA2 don't usually show up together, but in our family, both did. That meant two different sets of screening schedules, two different sets of terminology, and two different points of contact in the health system to keep track of, on top of the emotional weight of knowing our risk before anything had actually happened.

What we didn't have, early on, was a single place that explained things simply and pointed us toward Canadian resources instead of generic, often American, ones with different eligibility rules, different coverage, and different referral pathways than what we could actually access.

GCAA started as an Instagram page because that's where we were already processing this out loud. We're building it into something more structured: education, a real referral directory, and a community of people who don't need the basics re-explained to them, because we think every family navigating a hereditary cancer mutation in Canada deserves that starting point.

Learn

Understand what you're dealing with

Hereditary cancer syndromes are confusing on purpose: the science moves fast and the terminology is dense. Here's the plain-language version, covering the mutations we hear about most and the ones that don't get enough attention.

Hereditary cancer syndromes, in plain language

Each of these is caused by an inherited change in a single gene, passed down in an autosomal dominant pattern, meaning each child of a carrier has roughly a 50% chance of inheriting it.

BRCA1 / BRCA2

Hereditary Breast & Ovarian Cancer (HBOC)

Raises lifetime risk of breast, ovarian, prostate, and pancreatic cancer. Roughly 1 in 200 Canadians carries a BRCA1 or BRCA2 mutation; rates are higher in some founder populations, including French Canadian and Ashkenazi Jewish communities.

Source: Canadian Cancer Society

CDH1 / CTNNA1

Hereditary Diffuse Gastric Cancer (HDGC)

Sharply raises risk of diffuse-type (signet ring cell) gastric cancer and lobular breast cancer. Diffuse gastric cancer is hard to catch on a standard endoscopy, which is why risk-reducing gastrectomy is often discussed for carriers alongside annual screening.

Source: Canadian Cancer Society

MLH1 / MSH2 / MSH6 / PMS2

Lynch Syndrome

The most common inherited cause of colorectal and endometrial cancer, also linked to ovarian, gastric, and urinary tract cancers. Risk varies a lot by gene: MLH1 and MSH2 carriers generally face the highest lifetime colorectal cancer risk, MSH6 and PMS2 carriers somewhat lower.

Source: Canadian Cancer Society

TP53

Li-Fraumeni Syndrome

One of the broadest hereditary cancer syndromes, linked to early-onset breast cancer, sarcoma, brain tumours, adrenal cortical carcinoma, and several others, often across multiple generations.

Source: Canadian Cancer Society

PTEN

Cowden Syndrome

Raises risk of breast, thyroid, and endometrial cancer, and is associated with distinctive benign skin and mucosal growths that often show up before any cancer diagnosis.

Source: Canadian Cancer Society

APC

Familial Adenomatous Polyposis (FAP)

Causes hundreds to thousands of colon polyps starting in the teens or twenties, with a near-certain progression to colorectal cancer without surveillance and treatment.

Source: Canadian Cancer Society

STK11

Peutz-Jeghers Syndrome

Causes distinctive gastrointestinal polyps and dark pigmented spots on the lips and mouth, alongside increased lifetime risk of GI, breast, and reproductive-organ cancers.

Source: Canadian Cancer Society

PALB2 · CHEK2 · ATM · BRIP1 · RAD51C/D

Other panel-tested genes

Modern multi-gene panels test dozens of genes beyond BRCA and CDH1. Each carries its own risk profile and management guidelines. Ask your genetic counsellor which genes were actually included in your panel.

Source: GECKO, Genetics Education Canada

Positive, negative, and the confusing middle result

Positive

A known cancer-linked mutation was found. Your care team can now offer syndrome-specific screening and prevention options, and relatives can consider testing for that exact mutation.

Source: Canadian Cancer Society

Negative

No mutation was found in the genes tested. It doesn't erase a strong family history: your doctor may still recommend closer surveillance based on that history alone.

Source: Canadian Cancer Society

Variant of Uncertain Significance (VUS)

A DNA difference was found, but it isn't yet known whether it affects cancer risk. Most VUS results are eventually reclassified as more data comes in, and a VUS should not, on its own, change your medical care.

Source: Canadian Cancer Society

Previvor: Someone who carries a cancer-linked mutation but has not (yet) developed cancer.
Penetrance: How likely a mutation is to actually cause disease over a lifetime. It's rarely 100%.
Proband: The first person in a family identified with a mutation, who often triggers testing for relatives.
Cascade testing: Testing relatives of a confirmed carrier for that same specific mutation.

Get support

Real pathways, Canadian system

Access to hereditary cancer genetics varies by province. These are the Canadian starting points we trust most, for building your family history and for finding an actual genetic counsellor.

Start with your family history

Most referrals for genetic counselling happen because a pattern shows up across generations, not because of one diagnosis. Before your appointment, it helps to have that pattern written down.

Check your family history

Canadian Cancer Society's guide to what to gather and why, before you talk to your doctor.

cancer.ca

Ontario high-risk breast screening eligibility

How Ontario Health (Cancer Care Ontario) decides who qualifies for enhanced breast screening based on genetic test results or family history.

Cancer Care Ontario

Find a genetic counsellor

Canadian Association of Genetic Counsellors

National clinic-search tool to find genetics professionals near you.

genetic-counsellors.ca

Canadian Cancer Society

Plain-language explainers on genetic counselling and testing, plus a national support line.

cancer.ca

BC Cancer, Hereditary Cancer Program

Genetic counselling and testing for BC/Yukon residents; a model for what most provinces run through their cancer agency.

bccancer.bc.ca

Alberta Health Services, Hereditary Cancer Clinic

Referral information and general hereditary cancer education for Albertans.

albertahealthservices.ca

The Screen Project (Women's College Hospital, Toronto)

An accessible, guided BRCA1/BRCA2 testing program open to Canadians 18+, outside standard eligibility criteria.

thescreenproject.ca

Ovarian Cancer Canada

Hereditary risk and BRCA-specific information for people with a family history of ovarian cancer.

ovariancanada.org

Colorectal Cancer Canada

National patient organization with resources on Lynch syndrome and hereditary colorectal cancer risk.

colorectalcancercanada.com

Genetics Education Canada, Knowledge Organization (GECKO)

Evidence-based hereditary cancer resources built for Canadian healthcare providers, useful if you want the clinical detail.

geneticseducation.ca

Stories

Share your story

Previvor, carrier, VUS result, family member, or medical professional: your experience or perspective is what helps the next person navigating a result feel less alone. Submissions are shared privately with the GCAA team, and we'll only ever publish a story with your permission.

Awareness dates

Dates worth building content around

A rough annual calendar for posts, partnerships, and events.

Mar 22

Lynch Syndrome Awareness Day, a natural tie-in even though GCAA's founding focus is CDH1/BRCA2, since many families navigate more than one syndrome.

Sept to Oct

National Hereditary Cancer Week & Previvor Day, falling in the transition between Ovarian and Breast Cancer Awareness Months. Strong window for storytelling posts.

October

Breast Cancer Awareness Month, a good moment for BRCA1/2-focused screening content.

November

Stomach Cancer Awareness Month, the natural anchor for CDH1 / HDGC education.

Advocacy

The advocacy angle

Canada already has stronger legal footing here than most people realize, but most families have never heard of it, and coverage gaps still exist. This isn't just a Canadian issue either: equitable access to genetic services is an active international policy conversation.

The federal Genetic Non-Discrimination Act (2017) makes it a criminal offence for an insurer, employer, or anyone else offering a contract or service to require you to take, or disclose the results of, a genetic test. The Supreme Court of Canada upheld it in 2020.
Coverage for genetic testing, counselling, and preventive procedures like risk-reducing gastrectomy or mastectomy still varies by province and by test. This is a live advocacy gap GCAA can push on.

CMAJ: The Genetic Non-Discrimination Act

A Canadian Medical Association Journal summary of why the law matters and how it came to pass.

cmaj.ca

Canadian Coalition for Genetic Fairness

A coalition of 18 Canadian organizations advocating against genetic discrimination and educating the public on their rights.

ccgf-cceg.ca

WHO: Accelerating access to genomics for global health

A 2022 World Health Organization Science Council report on closing global gaps in access to genetic and genomic services, including cancer risk testing.

who.int

Get involved

Building this with us

GCAA is early: right now that's an advantage. Tell us how you'd like to help and we'll follow up from teamgcaa@gmail.com.

Join a support conversation

We're setting up a small, private space for people newly diagnosed with a hereditary cancer mutation to ask questions and connect.

Partner with GCAA

Genetic counsellors, clinics, and Canadian hereditary cancer nonprofits: let's talk about co-branded content or referral pathways.

Volunteer

Design, content, community moderation, event planning. Tell us what you're good at.