Staff
UDNF Team
Danielle Carnival, Ph.D. | she/her
Chief Executive Officer
Danielle Carnival, Ph.D. is a national leader in health, research, and policy. She led the White House Cancer Moonshot from 2021- 2025 which delivered more than 125 federal actions and steps from more than 250 private sector organizations to improve the experience and outcomes for people facing cancer. At the same time, she led a White House team to drive policy and programmatic progress in the areas of research and regulatory infrastructure, public health, and biosecurity, among others. As the inaugural CEO of I AM ALS, Dr. Carnival provided strategic leadership and management for the patient-driven organization that aims to provide key resources to the community and create opportunities for patients to lead progress and cures. As Vice President of the Biden Cancer Initiative, she led organizational, program, policy, and partnership development.Dr. Carnival also worked at the White House from 2010-2017, where she leveraged her scientific expertise to make progress in the areas of health and biomedical research policy, STEM education, and advancing equity and promoting diversity in STEM fields. She was integral in developing the framing and goals for the Cancer Moonshot, managed the team executing on those goals, led multiple White House Science Fairs and the White House Cancer Moonshot Summit, and contributed to signature reports and recommendation implementation from the President’s Council of Advisors on Science and Technology and the President's Job Council. Danielle Carnival earned her Ph.D. in Neuroscience from Georgetown University and a B.S. in Biochemistry from Boston College.
Michele Herndon, DNP, RN | she/her
Director of Support
Michele Herndon, DNP, RN, is the Director of Support for the UDNF. For the past two decades, she has served as a pediatric nurse, leader, and manager in an academic hospital setting. Michele is also the mother to Mitchell who enrolled in the UDN in 2017 after five years of symptoms. After genetic sequencing and a model organism study using fruit flies, his gene mutation was identified by the UDN. Mitchell died in 2019 from the ultra-rare disease that was ultimately named after him, Mitchell Syndrome. Michele and her family started the Mitchell & Friends Foundation to support families and raise both awareness and money for research into Mitchell Syndrome. Michele lives in St. Louis, MO and recently completed her Doctorate in Nursing Practice at the University of Missouri-Columbia.
Sarah Marshall, MSW | she/her
Community Program Manager
Sarah Marshall has a dual role at the UDNF both as Community Program Manager and a PEER member since 2018. Her work in undiagnosed and ultra-rare disease is fueled by the lived experience of caring for a child who has been undiagnosed and also by the inspirational work and stories of others in the undiagnosed community. With a Master’s Degree in social work, she is no stranger to advocacy work. For over 20 years, she has worked directly with women, children and families in health care circles to achieve optimal outcomes for all. In addition to working directly with patients, Sarah has leadership experience in health care and legislative advocacy, strategic planning and non-profit organizations.
Chase McGarry, LMSW | he/him
Patient Navigator
Chase McGarry, LMSW, is a Patient Navigator with UDNF. Chase brings with him over a decade of involvement in the field of Social Work, where he has used skills, such as Motivational Interviewing, rapport building, and collaborative problem solving, to help people of all ages. Chase has professional experience as a Health Coach on topics including Stress Management and Depression. He has also served in the role of a Case Manager, during which time he advocated for the best health outcomes of clients. Chase brings with him various strengths, including empathy, compassion, and non-judgmental constructive feedback. He has personal experience with undiagnosed diseases through his mother, who continues to seek treatment for her symptoms. Chase is detail oriented and enthusiastic to support your health journey in any way possible.
Christin Siscoe, MSN, RN, CPN | she/her
Senior Patient Navigator
Christin Siscoe, MSN, RN, CPN, a Senior Patient Navigator with the UDNF, has 18 years of nursing experience as a pediatric nurse, educator, and administrator. She has obtained numerous national certifications and awards for her compassionate care, innovative leadership style, and profound advocacy work. Christin also participates in healthcare mission trips to Bonao in the Dominican Republic where she provides free ENT surgeries yearly. She currently resides in Rayville, Louisiana with her sons, Ayden and Cooper, and niece Elaina. Cooper is a UDN patient and attended the DUKE site, where he was given a partial diagnosis of hereditary pancreatitis. Cooper and Christin still await his rare autoimmune/autoinflammatory diagnosis. Through Christin’s involvement with the UDN as a PEER Member, she dreamed of the day she could combine her advocacy work and nursing experience into a full-time job. With her recent move to a rural area in Louisiana, she is passionate about making sure all participants are well-served equitably.
Dana Sayer | she/her
Communications and Events Lead and Patient Navigator
Meet Dana, your Communications and Events Lead and dedicated Patient Navigator at UDNF. With nearly a decade of experience in Law Enforcement, Dana has seamlessly transitioned her passion for serving the community into the healthcare realm. Over the past few years, she has devoted herself to guiding patients through the intricate healthcare system, ensuring a smooth journey throughout their continuum of care. Fluent in Spanish, Dana brings empathy and understanding to her role, ensuring all patients feel heard and supported. Drawing from a deeply personal commitment, Dana has played a pivotal role in helping a dear friend navigate through her own undiagnosed disease over the past decade. This firsthand experience fuels Dana's empathy and understanding, making her not just a navigator but a compassionate advocate for those seeking answers. With Dana by your side, you're not just navigating; you're empowered.
Jennifer Tousseau | she/her
Navigation Resource Specialist and Senior Patient Navigator
Jennifer Tousseau, a Navigation Resource Specialist and Senior Patient Navigator, has over 10 years of experience as a patient advocate, managing initiatives that help support and improve rare disease patients' diagnostic journeys. Along with guiding patients to gain access to healthcare resources, she has co-authored medical literature and educational resources, supported the organization of major medical conferences, and represented patients in influential medical working groups. Her advocacy work started with her son's diagnosis of a rare autoinflammatory disease at the age of two, which led her to join the Autoinflammatory Alliance Board of Directors. As a patient navigator for the UDNF, she is committed to helping guide, support, and empower undiagnosed and rare disease patients and their families and caregivers facing complex medical challenges.