When Sierra was diagnosed with Visual Snow Syndrome (VSS), little was known about this condition, and it was extremely difficult for her to get a diagnosis. By founding the Visual Snow Initiative, Sierra moved mountains to increase awareness and help bring recognition, research, and support to millions worldwide.

VSS is a neurological condition that affects how the brain processes visual and sensory information. Sierra describes the sudden and terrifying onset of her symptoms at 21, when her vision changed permanently in an instant. She speaks candidly about the relentless nature of her condition—constant visual disturbances, sensory overload, and insomnia—and how these symptoms disrupted every aspect of her life. Yet, beyond the physical impact, it is the emotional toll of being dismissed, misdiagnosed, and left without answers that stands out most.

What begins as a conversation about an often-overlooked condition quickly unfolds into a powerful story of resilience, medical trauma, and advocacy. Sierra’s journey reflects a broader issue within healthcare: the difficulty patients face when their condition doesn’t fit established frameworks.

Throughout the episode, Sierra offers a compassionate and honest perspective on living with chronic illness. She reminds us that resilience is often not a choice, but something we are forced to build, and that even small victories matter. Her story is both heartbreaking and inspiring, shining a light on the unseen struggles many people carry and the quiet strength it takes to keep going.

The song Sierra chose is Legend by Chronixx.

Episode 84: Sierra Domb - Visual Snow Syndrome

Alexa’s daughter, Charlotte, lives with limb-girdle muscular dystrophy 2C (LGMD2C), a rare genetic disorder leading to childhood-onset progressive muscle weakness. In this discussion, Alexa takes us on a journey from an unexpected diagnosis at just two years old, to finding hope through groundbreaking gene therapy.

What stands out is the way Alexa describes living with the condition not as a single moment of impact, but as something that unfolds over time—something she is “still reacting to almost 10 years later.” The conversation gently explores the realities of parenting a child with a rare disease: the constant planning, the invisible challenges, and the emotional complexity of watching your child grow up faster than they should have to.

Charlotte’s story is not only one of medical complexity, but also of resilience, empathy, and perspective. From advocating for herself at school to comforting a nervous nurse at just four years old, she embodies a maturity shaped by lived experience. The episode also highlights the power of community and science, particularly the life-changing impact of gene therapy and the families who push boundaries to make treatments accessible.

Above all, this episode is about hope: hope found in progress, in people, and in the extraordinary spirit of a young girl who feels “weightless” in the ocean; a place where her condition momentarily disappears.

The song that Alexa chose is Hallelujah by Jeff Buckley.

Episode 83: Alexa Colella - LGMD2C

Kelly and Avery are two advocates living with Collagen VI-related congenital muscular dystrophy (CMD), an ultra-rare neuromuscular condition that causes progressive muscle weakness and impacts mobility and respiratory function.

They share their personal journeys with disability, discussing how their condition shaped their childhood, their transition to using power wheelchairs, and the societal assumptions they have had to challenge along the way. What emerges is not a story defined by limitations, but one of determination and community.

Beyond their personal experiences, both guests highlight the importance of advocacy – from mentoring younger people with CMD to participating in Rare Disease Week on Capitol Hill to raise awareness and influence policy. Their reflections underscore the urgency of improving diagnosis timelines, increasing research access, and ensuring people with disabilities are included in decisions that affect them.

Kelly and Avery host their own podcast, Wheel Talks, which provides a space for honest conversations about disability, independence, and representation. Their voices bring warmth, honesty, and hope about living fully while navigating a rare condition.

Ultimately, this episode is a powerful reminder that visibility, storytelling, and community can create meaningful change.

Episode 82: Kelly Berger & Avery Roberts - Collagen 6

Carter lives with multiple conditions, and this episode is focused on two of them: Ehlers-Danlos Syndrome (EDS) and Mast Cell Activation Syndrome (MCAS). Carter’s story is one of quiet endurance, misdiagnosis, rediscovery, and ultimately purpose.

Born with classical EDS caused by a collagen gene variant, Carter spent two decades sensing “something wasn’t quite right” before receiving a diagnosis. Years of chronic pain, joint instability, GI issues, and nerve problems were compounded by mast cell symptoms that mimicked psychiatric illness – hallucinations, mood swings, anxiety.

We discuss the profound shift after Carter’s diagnosis and receiving the right treatment for MCAS: clearer thinking, emotional stability, and physical relief. Deeper than the physical symptoms, Carter speaks with wisdom about reclaiming selfhood and finding peace. He also reflects on discovering a community who understands him, and finding a purpose in advocacy.

Carter’s reflections on resilience, stigma in healthcare, identity, and hope are thoughtful and deeply human.

The song that he chose is Standing Outside the Fire by Garth Brooks.

Episode 81: Carter Hemion - EDS & MCAS

Sylvain speaks with Roberta about living alongside Alagille syndrome through her daughter Chloe’s journey. Roberta shares what it means to parent a child with a rare, multi-system condition, from the shock of an early diagnosis, to years dominated by relentless itching, sleep deprivation, and the emotional weight of watching her child suffer.

The conversation explores not only the medical realities of Alagille syndrome, but also the invisible burdens placed on caregivers, particularly when support systems fall short. Roberta reflects on the life-changing impact of clinical trials, the complexities of liver transplantation, and the long road toward independence for a young adult living with a chronic illness. Throughout, there is a quiet but powerful thread of hope, grounded in medical progress, community, and the small, human moments that sustain families through unimaginable challenges.

The song Roberta chose is Here Comes The Sun by the Beatles.

Episode 80: Roberta Smith - Alagille Syndrome

Brandon shares a deeply personal and grounded account of living with granulomatosis with polyangiitis (GPA), a rare and potentially life-threatening autoimmune vasculitis. Brandon walks us through his diagnosis as a young Division I athlete, the long road to remission, and the physical and emotional toll of repeated relapses, impacting his lungs, kidneys, and identity as a runner.

Beyond the medical realities, this conversation gently explores grief, mental health, and the quiet isolation that often accompanies rare disease, especially in a sport environment when there is a pressure – external or self-inflicted – to “push through”.  Brandon reflects on learning to listen to his body, manage stress, and redefine success away from constant striving.

The episode also highlights the power of community, advocacy, and shared stories through Brandon’s work with the Vasculitis Foundation, a reminder that inspiration doesn’t always come from extraordinary achievements; sometimes it comes from showing up, telling the truth, and helping others feel less alone.

The song that Brandon chose is Father’s Son by Steven Wilson Jr.

Episode 79: Brandon Hudgins - GPA

Sylvain speaks with Gay Grossman about life with ADCY5, a rare genetic movement disorder, and the journey she and her daughter Lilly have travelled together. Gay shares the long and often lonely road to diagnosis, the physical realities of a condition that affects the body but not the mind, and the quiet resilience Lilly has shown since childhood. The conversation moves through years of misdiagnosis, advocacy in schools, sleepless nights, and relentless problem-solving, before arriving at a moment of transformation: a treatment discovered through community, research, and lived experience that has profoundly changed Lilly’s quality of life. Above all, this episode is a story about perseverance, parental advocacy, and the belief that understanding the root cause can change everything, not just for one family, but for many.

The piece of music that Gay chose is Canon by Johann Pachelbel.

Episode 78: Gay Grossman - ADCY5

Marguerite shares the story of her son Louis and their life with Prader-Willi syndrome (PWS), a complex rare disease. Marguerite speaks with honesty, warmth and clarity about the medical, emotional and practical realities of raising a child with a rare genetic condition, from Louis’s fragile start in neonatal intensive care to adulthood in a specialist supported living environment. She explores complex themes such as food security, anxiety, autism, and the invisible labour of caregiving, while challenging societal assumptions about success, independence and what a “good life” looks like. Marguerite is a strong advocate for the PWS community, and the importance of social care for children and families dealing with a rare condition. This episode is ultimately a powerful reminder that with understanding, routine, community and the right support, people with Prader-Willi syndrome can live happy, meaningful lives – and that listening to those with lived experience is essential.

The song that Louis chose is Say Something by Justin Timberlake featuring Chris Stapleton.

Episode 77: Marguerite Hughes - PWS

This is the story of Yiannis, nicknamed “Mr. Sunshine”, told by his mother Angela. Yiannis is a 5-year-old boy who lives with the ultra-rare IRF2BPL-related disorder, which has affected his development in many ways. Angela describes the profound ways in which this condition has reshaped their lives, and how hope is their drive to make a difference for Yiannis and other children affected by IRF2BPL.

Angela’s story is one of fierce advocacy and unconditional love. After Yiannis’ diagnosis, she and her husband founded Yellow for Yiannis, a foundation devoted to advancing research into the condition and supporting other families facing similar diagnoses. Angela balances the day-to-day joy of raising her son, with her fight to be heard by the scientific community to find a suitable treatment for Yannis.

Music, especially “Here Comes the Sun” by The Beatles, plays a central role in their lives. Angela naturally selected this song for this episode.

Episode 76: Angela Papazoglou - IRF2BPL

Kayleigh opens up about living with Addison’s disease, a rare condition where the adrenal glands fail to produce enough cortisol. Diagnosed at just 15, Kayleigh describes the medical journey that led to her diagnosis, the daily routines that keep her well, and the emotional resilience she’s built along the way. Despite the challenges of balancing chronic illness with study and performance dreams in musical theatre, she radiates optimism and determination.

Kayleigh’s story is one of strength, self-awareness, and adaptability – from planning university choices around nearby endocrinology hospitals to managing stress and illness triggers with remarkable maturity. Her openness about wanting more chronic illness representation in theatre is inspiring, as she reminds listeners of the importance of visibility and empathy.

The song that Kayleigh chose is The Chain by Fleetwood Mac.

Episode 75: Kayleigh Berkoski - Addison's Disease

On One Condition is a podcast for anyone who wants to learn about a specific health condition. Hear from people who live with a condition, how it affects them and how they manage it. Sylvain Berthelot has worked in the clinical trial industry for over a decade. He is naturally curious and passionate about how the body functions. Through his interviews, he aims to give fellow human beings a voice, spreading the word about the multitude of medical conditions that affect us.

Sylvain Berthelot

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