Rare diseases affect small patient populations, yet their collective impact is profound. With one in 10 Americans living with a rare disease, this is an urgent public health challenge that touches every community. These conditions are complex and lifelong, often leaving patients and their families to endure years of unexplained symptoms, limited treatment options, and insufficient public awareness. 

One example is hypoparathyroidism, or hypopara, a rare endocrine disease that is frequently overlooked, largely because its symptoms overlap with those of more common medical disorders. Often mischaracterized as a simple calcium deficiency, hypoparathyroidism is, in fact, a parathyroid hormone deficiency disease, which is an important distinction that remains misunderstood by many healthcare providers, and even specialists.

“Hypoparathyroidism may be rare, but for those living with it, the impact is profound,” says Patty Keating, executive director of the HypoPARAthyroidism Association. “People with hypoparathyroidism have struggled to have their experience recognized. As understanding of the condition has grown, meaningful treatment options have emerged, but access remains a barrier. Utilization management tools like step edits and new-to-market blocks too often prevent patients from receiving newly approved therapies.”

It is such areas of significant unmet medical need that Ascendis Pharma is committed to addressing, developing therapies that make a meaningful difference in people’s lives. Together with advocacy partners, healthcare providers, and patient communities, Ascendis has been raising awareness of hypoparathyroidism and advocating for change in the standard of care with the goal of improving health and quality of life for this community.

Hypopara: A rare disease with an outsized burden

Hypopara is caused by insufficient or absent parathyroid hormone (PTH), a hormone essential for regulating calcium and phosphate balance in the body. Although considered rare, hypopara affects an estimated 200,000 people worldwide, including approximately 70,000 to 90,000 people in the United States. While hypopara can result from genetic or autoimmune causes, it most often results after neck surgery, when the parathyroid glands may be unintentionally damaged or removed. Unfortunately, some patients are not informed that hypopara can be a potential complication of their surgery.  

Hypopara can be challenging to diagnose. Historically, limited awareness among healthcare providers has contributed to many patients experiencing long delays in diagnosis, misdiagnoses, and inconsistent care, leaving patients without clear answers for years. Once diagnosed, patients often find that managing hypopara can be both physically and emotionally demanding.  

People living with the disease may experience a wide range of symptoms, including muscle spasms, numbness and tingling, fatigue, and cognitive dysfunction often described as brain fog. These symptoms can fluctuate unpredictably and disrupt daily life — ranging from mildly inconvenient for some to severely debilitating for others. 

Insights from the Hypoparathyroidism Voice of Patient Report, developed through an Externally Led Patient-Focused Drug Development (EL-PFDD) meeting, illustrate the full scope of this burden. Among the hundreds of participants, the most concerning symptoms reported were cognitive dysfunction, muscle cramps, and fatigue. Patients identified loss of functioning, symptoms worsening, and the need for long-term care as their greatest concerns for the future. 

“Living with hypoparathyroidism feels like constantly walking on a tightrope,” one participant shared. “Never knowing when I might fall — or when my own body might betray me — is overwhelming.” 

Patient-centricity is key for transforming the future of rare endocrine disease treatment 

Ascendis Pharma’s commitment to serving people with high unmet medical needs comes into a sharp focus in the area of hypopara. The company has emerged as a leader in the space. Together with advocacy partners and patient communities, Ascendis Pharma is raising awareness of hypopara as a disease caused by insufficient levels of parathyroid hormone and not simply a calcium deficiency.

Advancing rare endocrine disease treatments depends on a shared effort — including contributions from patients, caregivers, clinicians, researchers, advocacy organizations, policymakers, and industry. Increasingly, patient experience is being recognized not just as personal testimony, but as essential insight that helps shape research priorities, care models, and innovative treatment approaches. 

Guided by its core values of Patients, Science, and Passion, Ascendis Pharma has become a leading developer of therapies. At the center of Ascendis Pharma’s work to address deep unmet medical needs is TransCon®, the company’s innovation platform for drug development.

Together with a wide range of stakeholders, Ascendis Pharma is committed to bringing greater awareness, education, and access to rare disease care, recognizing that progress in delivering meaningful improvements in treatment requires listening first. Listening to the patients’ voices and incorporating their perspectives to better understand what is important to them in managing their condition is crucial for making improvements in diagnosis and care. The more we embed patient voices in the process, the more likely we are to create solutions that truly meet the needs of those they are intended to serve.