On Rare

Severe high blood pressure and an unexplained feeling of heaviness led Adrienne to the emergency room at age 26, where scans revealed cysts throughout her kidneys and ultimately led to a diagnosis of autosomal dominant polycystic kidney disease (ADPKD). With no family history of the condition, Adrienne learned that her ADPKD was caused by a spontaneous genetic mutation.
In this episode of On Rare, David Rintell, Head of Patient Advocacy at BridgeBio, and Mandy Rohrig, Vice President of Patient Advocacy at BridgeBio, speak with Adrienne about navigating the uncertainty of a new diagnosis, recurrent hypertensive crises, and the discovery of brain aneurysms that eventually required a craniotomy. Adrienne also shares how finding the PKD community helped her feel less alone and inspired her to become a mentor, advocate, and patient voice in research and policy.
Nile Abularrage, Senior Director of Business Development and Operations at GondolaBio, provides a scientific overview of ADPKD. ADPKD is a genetic condition that causes fluid-filled cysts to progressively grow in the kidneys, which can enlarge the kidneys and lead to pain, high blood pressure, and declining kidney function over time. While ADPKD is most often inherited from a parent, it can also result from a spontaneous genetic mutation, as it did for Adrienne. Nile also explains how ADPKD can affect other parts of the body, including an increased risk of intracranial aneurysms and cysts in the liver. While treatment options remain limited, he shares why this is an exciting time for ADPKD research, with growing interest and a number of promising approaches being explored for the community.

Excruciating pain after even brief sun exposure, years without answers, and a life-threatening liver crisis shaped Ashley's journey with erythropoietic protoporphyria (EPP), a rare genetic condition that causes severe photosensitivity. Although Ashley experienced symptoms beginning in early childhood, she wasn't diagnosed until after her 40th birthday, when she was hospitalized with advanced liver disease ultimately requiring a transplant. In this episode of On Rare, David Rintell, Head of Patient Advocacy at BridgeBio, and Mandy Rohrig, Vice President of Patient Advocacy at BridgeBio, speak with Ashley about her decades-long diagnostic journey, the emotional experience of waiting for a donor organ, and how finding a physician living with porphyria finally led to answers. Ashley reflects on the challenges of living in the shadows to avoid sunlight, navigating life after transplant, and why sharing her story has become one of her greatest purposes. 

Dr. Pete Schmidt, Chief Medical Officer of GondolaBio provides a medical overview of EPP and X-linked protoporphyria (XLP). Both conditions are rare genetic disorders caused by the buildup of protoporphyrin IX, a molecule that becomes highly reactive when exposed to visible light. This reaction causes severe pain and inflammation in the skin after sun exposure and, in some people, can lead to progressive liver damage as protoporphyrin accumulates in the liver and bile ducts. Dr. Schmidt explains the underlying biology of EPP, why symptoms can be difficult to diagnose, and the challenges of managing both the painful photosensitivity and the risk of liver disease.

Severe seizures, nonstop crying, and an exaggerated startle reflex marked the beginning of Elliott’s journey with molybdenum cofactor deficiency type A (MOCD type A), an ultra-rare inherited metabolic disorder that can cause devastating neurological damage shortly after birth. After initially being told that Elliott would likely not survive to school age, his family was offered access to an experimental treatment that changed the course of his life. In this episode of On Rare, David Rintell, Head of Patient Advocacy at BridgeBio, and Mandy Rohrig, Senior Director of Patient Advocacy at BridgeBio, travel to England to meet Elliott and his family and hear how they navigated diagnosis, uncertainty, and hope after already experiencing the heartbreaking loss of another child. Geoff and Lucy, Elliott’s parents, reflect on the emotional toll of diagnosis, the realities of managing complex medical care at home, and the joy of watching Elliott grow, attend mainstream school, and live life alongside his siblings. Their story highlights the importance of early diagnosis, caregiver resilience, and the life-changing impact of treatment for rare disease families.

Dr. Günter Schwarz, Professor of Biochemistry at the University of Cologne and a leading expert in MOCD, provides a medical overview of the condition. MOCD is a rare inherited metabolic disorder caused by the body’s inability to produce molybdenum cofactor, which is required for several critical enzymes to function properly. Without it, toxic sulfite builds up in the body, particularly in the brain, leading to severe seizures, neurological injury, and often early death. Dr. Schwarz explains how the condition is inherited, why symptoms begin so early in life, and how targeted treatment can dramatically alter outcomes when started quickly after diagnosis.

Seizures, incorrect diagnoses, and years of unanswered questions shaped Arielle’s journey with autosomal dominant hypocalcemia type 1 (ADH1). ADH1 is a rare genetic condition in which the body is unable to accurately sense blood calcium levels, leading to hypoparathyroidism. Although she grew up aware that her calcium levels were low, she did not receive a formal diagnosis until age 16, when a severe calcium crash led to a seizure and ultimately revealed the underlying cause. Years later, when her young son Sebastian began experiencing seizures, Arielle recognized familiar warning signs of abnormal calcium levels. Despite a known family history of abnormal calcium levels, his symptoms were initially misdiagnosed, resulting in repeated hospital visits and increasing concern, until genetic testing for hypoparathyroidism ultimately confirmed a diagnosis of ADH1.

In this episode of On Rare, David Rintell, Head of Patient Advocacy at BridgeBio, and Mandy Rohrig, Senior Director of Patient Advocacy at BridgeBio, speak with Arielle about navigating life with ADH1 and advocating for answers. She shares the realities of managing a condition that can quickly become life-threatening, from muscle spasms and seizures to hospitalizations and kidney complications, while raising a family and pushing for a diagnosis. Her story highlights the importance of persistence, listening to one’s own instincts, and continuing to ask questions when something doesn’t feel right, while  underscoring the power of a family coming together to find answers to a condition that has affected generations.

Dr. Scott Adler, Chief Medical Officer of BridgeBio affiliate Calcilytix and a nephrologist, provides a medical overview of ADH1. Abnormal calcium levels can cause muscle spasms, and severe seizures, and painful muscle contractions known as tetany. About 80% of ADH1 cases are usually inherited in an autosomal dominant pattern, meaning they can be passed down from one affected parent. The remaining cases occur spontaneously, with no family history of the condition. ADH1 is currently managed with oral calcium and active vitamin D supplementation, although maintaining stable levels is challenging and may lead to complications over time.

In this episode of On Rare: Innovators, hosts David Rintell, Head of Patient Advocacy at BridgeBio, and Mandy Rohrig, Senior Director of Patient Advocacy at BridgeBio, speak with Kat Bryant Knudson, Founder and CEO of the Speak Foundation and a leader in the limb-girdle muscular dystrophy (LGMD) community. Diagnosed as a child after experiencing early symptoms of muscle breakdown, Kat spent years searching for answers before receiving a definitive genetic diagnosis. What began as a personal journey to understand her condition evolved into a lifelong commitment to ensuring that no one with LGMD faces that journey alone.

From founding the Speak Foundation in an unexpected twist of fate to organizing groundbreaking scientific workshops that bring patients, researchers, industry, and the FDA to the same table, Kat has helped reshape how the LGMD community connects, advocates, and advances research. Guided by the belief that people with lived experience should have the loudest voice in the room, Kat continues to innovate on behalf of a diverse and growing rare disease community.

Kat’s story is a reminder that progress begins with connection, shared experience, and the courage to speak up.

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