About HTAD and CAN-ACT

What is HTAD?

Heritable Thoracic Aortic Disease (HTAD) refers to a group of rare, often underdiagnosed genetic conditions that cause the aorta, the main blood vessel leaving the heart, to enlarge, resulting in an aneurysm, or tear, leading to a dissection, particularly in the thoracic region. These conditions are typically silent until a life-threatening event occurs, such as an aortic dissection or sudden death due to rupture. Alarmingly, only a small percentage of individuals experience symptoms before such acute events.

HTAD can occur in isolation or as part of a broader genetic syndrome, such as Marfan syndrome, Loeys-Dietz syndrome, or vascular Ehlers-Danlos syndrome. These syndromic forms often affect multiple organ systems and are linked to disruptions in connective tissue or signaling pathways like TGF-β. Nonsyndromic HTAD, by contrast, often appears solely as thoracic aortic disease, but may still have a familial genetic basis.

Advances in genetics have transformed our understanding and diagnosis of HTAD, allowing for earlier detection through family screening and identification of genotype–phenotype patterns. However, delays in diagnosis remain common, especially in young individuals, due to the rarity of these diseases and fragmented healthcare systems.

Managing HTAD requires lifelong monitoring and a multidisciplinary team familiar with its complexities. Medications like beta-blockers or angiotensin receptor blockers can slow disease progression, and early surgical intervention is critical in preventing catastrophic outcomes. Despite these advances, data on HTAD in Canada, especially in children and young adults, remains limited, highlighting the urgent need for dedicated research and coordinated care.

What is the CAN-ACT Patient Registry?

The Canadian Aortopathy and Connective Tissue Disorders (CAN-ACT) Registry is a national initiative led by the Loeys-Dietz Syndrome Foundation Canada in partnership with clinical institutions across the country. It is designed to collect and organize health data from individuals diagnosed with heritable thoracic aortic diseases (HTAD), such as Loeys-Dietz syndrome, Marfan syndrome, and related conditions.

Patient registries like CAN-ACT play a critical role in rare disease research by serving as a central hub that connects patients, clinicians, and researchers. By gathering detailed, long-term information on patient experiences, genetic profiles (genotypes), clinical symptoms (phenotypes), imaging results, treatments, and outcomes, registries help:

  • Improve understanding of how HTADs progress
  • Support earlier diagnosis and more accurate treatment
  • Highlight disparities in access to care across regions
  • Identify symptoms that may otherwise go unrecognized
  • Enable faster, better-informed clinical trials
  • Empower patient advocacy and policy change

The CAN-ACT Registry aims to build a well-characterized national database of pediatric and adult HTAD patients. This will not only support collaborative research but also contribute to better care, quality of life, and long-term outcomes for individuals living with these rare but life-threatening conditions.

Patients who participate in the registry contribute to a growing body of knowledge that can drive meaningful change, not just for themselves, but for future generations facing HTAD.