Newborn Genome Screening Is Here: GUARDIAN, Rett & Rare Disease | Dr. Wendy Chung

Dr. Wendy Chung

Clinical geneticist and newborn sequencing leader

“In one week I diagnosed a 72-year-old with Rett syndrome and a three-week-old with Rett syndrome.” Newborn genome sequencing isn’t science fiction anymore. It’s already changing which babies get diagnosed, when they get treated, and how many families spend years in diagnostic limbo. When our daughter Evie started missing her milestones, we spent five years bouncing between specialists, MRIs, EEGs, blood tests, microarrays and more—with no answers. It took whole exome sequencing to finally reveal a point mutation in SHANK3, now known as Phelan-McDermid syndrome. Our story is heartbreakingly common for families with genetic disorders—and the emotional and economic cost is huge.  In this episode of GENEration Hope, recorded October 2024, I sat down with Dr. Wendy K. Chung—clinical and molecular geneticist, Chair of Pediatrics at Boston Children’s Hospital and Harvard Medical School, and Principal Investigator of the GUARDIAN newborn genome screening study. We talk about: • How whole-genome sequencing (gWGS) is changing newborn diagnosis • What the GUARDIAN study is finding in over 13,000 babies so far • Why Rett syndrome is far more common than we thought (around 1 in 2500 girls)*Updated Nov '25 • The week she diagnosed a 72-year-old and a 3-week-old with Rett • The ethics of telling parents about serious conditions when babies still look “perfectly fine” • How families can “stand up and be counted” in registries so they’re not left out of future trials • Why early diagnosis is essential for gene-targeted therapies—and why timing may one day mean treating even before birth Since we recorded this interview, there’s been major movement in the field. At ICoNS’25 (International Consortium on Newborn Sequencing) in London, the conversation shifted from “Can we do genomic newborn screening?” to “How do we implement it responsibly?” Pilot programs like PERIGENOMED, BabySeq, GUARDIAN, the Generation Study, BabyScreen+ and BabyDetect are showing that careful real-world experience is key to scaling safely. The focus now is on scientific rigour, ethics, public trust, and genuinely including families and rare-disease communities in decisions that affect them.  We’re also seeing real momentum from places like the UK, Italy, Abu Dhabi, Canada, the Democratic Republic of the Congo, France, Saudi Arabia, Greece and Ecuador—all taking different paths toward the same goal: giving babies and families answers much earlier in life.  If conversations like this help you understand what’s coming—or give you hope for families like mine—please subscribe, like, and share this video so more families, clinicians, and researchers can find it. To see the latest updated information on Guardian as of Oct 2025, #GENErationHope #NewbornGenomes #RareDisease #RettSyndrome #NewbornScreening #GeneTherapy ⸻ • 🌐 GENEration Hope website: generationhope.co • 🧬 Learn more about GUARDIAN: • 📺 More interviews (Monica Coenraads, Alex Kolevzon: Chapters 1. 00:00 – A 72-year-old and a 3-week-old with Rett 2. 00:24 – Evie’s five-year diagnostic odyssey 3. 01:16 – How whole-genome sequencing changes newborn diagnosis 4. 01:46 – Intro: GENEration Hope at the ICoNS conference 5. 02:31 – Who is Dr. Wendy Chung? 6. 02:53 – From PKU to a 35-year journey in genetics 7. 05:03 – “Everyone, every child, every newborn” – Wendy’s 20-year vision 8. 06:12 – The three enabling technologies for cures (target, delivery, timing) 9. 08:19 – Treating babies—and maybe fetuses—“just in time” 10. 09:01 – Quick break: why subscribing really matters 11. 11:12 – The SMA newborn screening pilot that changed everything 12. 13:12 – From near-certain death to walking by age one 13. 14:22 – Duchenne, newborn screening, and getting impatient 14. 15:07 – Why whole-genome sequencing for all newborns? 15. 18:05 – GUARDIAN: 13,000 babies, 450 genes, and 3% positives 16. 19:19 – Rett is far more common than we thought 17. 20:01 – Holding her breath for the GUARDIAN Rett babies 18. 22:35 – Should parents be told when there’s no treatment yet? 19. 23:41 – The “honeymoon” of a healthy-looking baby vs. heavy news 20. 25:09 – Letting parents “choose their own adventure” on when to know 21. 27:16 – ICoNS and sharing GUARDIAN data with the world 22. 28:04 – Rett prevalence and why the numbers were wrong 23. 30:31 – How GUARDIAN actually works for parents in New York 24. 32:30 – What do parents want to know? (And how sure do we need to be?) 25. 37:19 – Privacy, law enforcement, and dried blood spots 26. 40:11 – “I truly do have hope in my belly” 27. 41:28 – “Stand up and be counted” – why registries matter 28. 43:35 – Using AI and home data to speed up trials 29. 47:18 – ICONS’25 update: the global state of gNBS 30. 48:22 – Outro: how you can help by sharing these stories