#399 How PKU Changed Newborn Screening Forever

CRISPR has carried enormous promise since scientists first realized its potential to edit the human genome, but it has also raised some of the biggest ethical questions in modern genetics. In this episode, Kira Dineen sits down with Dr. Kiran Musunuru to trace the evolution of human gene editing, beginning with the controversial 2018 announcement that scientist He Jiankui had used CRISPR to edit human embryos in China, resulting in the birth of the world’s first gene-edited babies. The experiment, which targeted the CCR5 gene in an attempt to reduce susceptibility to HIV, sparked international condemnation and intensified debate over germline genome editing, where genetic changes could potentially be passed on to future generations. From there, the conversation shifts to a dramatically different application of CRISPR: treating serious genetic disease in an individual patient. Dr. Musunuru shares the remarkable story of Baby KJ, who was born with severe carbamoyl phosphate synthetase 1 (CPS1) deficiency and became the first patient to receive a personalized CRISPR-based therapy designed specifically for his genetic variant. The team developed KJ’s customized base-editing treatment in approximately six months, moving from identification of his variant through preclinical testing, manufacturing, regulatory review, and ultimately treatment. Dr. Musunuru explains how KJ’s therapy works, what researchers have learned from his response so far, and whether his case could establish a new pathway for treating patients with ultra-rare genetic conditions who may never fit into a traditional drug-development model. This interview was recorded in person at AGBT Precision Health in Coronado, California, we caught up with Dr. Musunuru after a presentation. Episode Discussion Topics:

Please note this episode is only available on our website, DNAToday.com under Episode 415, and access is limited to those in the United States. In just a few years, achondroplasia treatment has expanded from no approved precision medicines to multiple approaches targeting the condition’s underlying biology. In this episode, we continue our conversation with Dr. Ravi Savarirayan, a global leader in skeletal dysplasia care and a lead investigator across multiple achondroplasia clinical development programs. Dr. Savarirayan previously joined us on Episode 401, where we explored the first approved precision treatment for achondroplasia and international guidance for its use. This time, we take a broader look at the rapidly evolving achondroplasia treatment landscape, including how different therapeutic approaches target FGFR3 signaling, how researchers interpret clinical trial outcomes, and what results from the Phase 3 PROPEL 3 study of investigational infigratinib could mean for children and families. We also discuss why treatments cannot be reliably compared using results from separate clinical trials, the importance of studying outcomes beyond growth, and the questions that remain about long-term safety, functional benefits, treatment selection, and switching therapies. Thank you to BridgeBio for sponsoring this episode. Episode Discussion Topics

When patients relocate or relatives living abroad need cascade testing, finding a qualified genetics professional in another country can be surprisingly difficult. The new Global Genetics Directory aims to change that through a free, verified, peer-to-peer resource connecting genetics and genomics professionals worldwide. In this episode of DNA Today, recorded in person at our studio, host Kira Dineen is joined by genetic counselor Monisha Sebastin, Founder and Principal Investigator of the Global Genetics Directory. Monisha explains how her international background and leadership within the genetics community revealed the need for a centralized global resource. We explore how the directory was developed with support from the prestigious Audrey Heimler Special Projects Award, how professionals are verified across different credentialing systems, and why the team chose a closed, consent-based model rather than a publicly searchable directory. Monisha also shares how the directory could strengthen cross-border patient care, cascade testing, professional collaboration, and access to genetics services around the world. Episode Discussion Topics

For most people, eating is an ordinary part of the day. But when you have phenylketonuria (PKU), every meal can involve calculations, preparation, medical monitoring, and decisions that affect how your brain and body feel. This is DNA Today, a podcast from Gene Pool Media, where we explore the breakthroughs, challenges, and human impact of genetics and genomics. I’m your host Kira Dineen, a genetic counselor and award-winning science podcaster and speaker. This is a continuation of our PKU series, sponsored by PTC Therapeutics. In the first episode (Episode 399), we explored how PKU helped launch newborn screening and why early diagnosis can completely change a child’s future. In this second episode, we’re looking at what comes next: what it actually means to manage PKU through food, and how this affects school, friendships, celebrations, mental health, independence, and a person’s relationship with food. Joining us are a mother and daughter who have experienced that journey together: Dr. Jennifer Brown is a geneticist, science communicator, and author of When the Baby Is Not OK: Hopes & Genes, a wonderful memoir about genetics, motherhood, and raising children with PKU. Lillian Isabella is a playwright, advocate, and graduate student in Columbia University's Narrative Medicine program who served six years on the National PKU Alliance board and lives with PKU. She is Dr. Brown's daughter. Our guests are participating in this podcast to share their experience and opinions only. They are not providing any medical advice. Always check with your healthcare provider for treatment and screening advice.

Prenatal cell-free DNA screening is designed to assess a pregnancy for chromosome conditions; but in rare cases, it can reveal something entirely unexpected about the pregnant patient’s own health. In this episode, Kira Dineen is joined in-person by Dr. Diana Bianchi to explore how unusual or non-reportable cfDNA screening results can sometimes be a signal of an undiagnosed maternal cancer. Dr. Bianchi shares findings from the NIH’s ongoing IDENTIFY study, which is investigating why these unexpected cfDNA patterns occur, how clinicians can distinguish potential malignancy from other explanations, and what should happen next when a prenatal screening result raises concern about maternal cancer. We recorded this episode in person at AGBT Precision Health, one of our favorite conferences of the year. The conference wrapped this past Wednesday and brought together leaders across genomics, precision medicine, research, and clinical care in an intimate setting that makes it easy to connect, learn, and have thoughtful conversations. The conference is also hosted at a beautiful resort in the San Diego area, which makes the experience especially memorable. We highly recommend attending next year’s AGBT Precision Health meeting, taking place September 13–15, 2027, at the same gorgeous location. We already put it on our calendars!