The Rarest Diagnosis. The Most Determined Family.

HCS — Hajdu-Cheney Syndrome — is one of the rarest conditions on earth. Fewer than 100 people worldwide have been documented with this diagnosis. It affects bones, joints, organs, and nearly every system in the body through a mutation in the NOTCH2 gene, causing progressive bone loss, acroosteolysis (breakdown of the fingertip and toetip bones), severe osteoporosis, and a range of neurological and cardiovascular complications.

There is no cure. There are no established treatment guidelines. And until recently, there was no research conference — no moment where the world's specialists sat in the same room and committed to changing that. Until now.

Documented cases worldwide

<100

Approved treatments or guidelines

0

Year first described — still understudied

1948

Meet the HCS Blue & Gold Team

When Gia was diagnosed with Hajdu-Cheney Syndrome, her parents — both proudly retired Philadelphia Police Officers — did what people who have spent careers running toward hard things do. They got to work.

Susan and her husband founded the Hajdu-Cheney Syndrome Foundation to drive research and accelerate the development of treatments for this condition that the medical world barely knew existed. They didn't wait for a specialist to lead the way. They became the specialists in finding one.

"Children's Hospital of Philadelphia has agreed to host the first research conference dedicated to advancing treatments and scientific understanding of HCS at CHOP's Center for Bone Health, in partnership with our Foundation. This conference will bring together leading experts to accelerate collaboration and progress."

— Susan Macartney, HCS Blue & Gold Team · February 27, 2026

Where Every Dollar Goes

All funds raised by the HCS Blue & Gold Team through the I Heart CHOP Run/Walk go directly toward supporting the first-ever HCS research conference at CHOP's Center for Bone Health.

While CHOP focuses on children, the research and collaboration generated through this effort will benefit both children and adults living with HCS. Donations go through the Children's Hospital of Philadelphia Foundation — a US 501(c)(3) nonprofit, established in 1855 as the nation's first children's hospital.

• 🏥

  First-Ever HCS Conference

  Funds go directly to CHOP's Center for Bone Health to convene the first research conference dedicated entirely to HCS.

• 🔬

  Closing a Real Gap

  No treatment guidelines exist. This conference brings together leading experts to accelerate the research that could change that — for patients alive today.

• 👐

  Adults Included

  Though CHOP is a children's hospital, the research will explicitly include and benefit adult patients living with HCS.

• 🤝

  Patient-Led

  A family with a diagnosis didn't wait for the system to move. They built a foundation, partnered with CHOP, and are now fundraising to make it real.

Bare Your Rare Stands With the HCS Community

At Bare Your Rare, this is exactly the kind of moment we exist to amplify. A family living with a diagnosis that fewer than 100 people on earth share, building infrastructure from scratch — a foundation, a hospital partnership, a fundraising campaign — because the research world hasn't caught up yet.

We are proud to support Susan, Gia, and the entire HCS community in pushing this forward. The blue and gold of this campaign aren't just colours borrowed from a family's history of service. They're a declaration: this community is organized, this cause has champions, and HCS is no longer waiting in the dark.

Whether you're living with HCS, part of the rare disease community, or simply someone who believes every rare condition deserves a fighting chance — donate, share, and make some noise. Rare Disease Day is coming. This is our moment.