Inside Science podcast: gene therapy breakthroughs, aging brain insights, and Ethiopian volcano dynamics

In this Inside Science episode, experts discuss how gene therapy is moving from rare disease case reports to broader platforms, the four turning points in how white matter connects in the aging brain, and insights from both old and new telescopes studying the cosmos. The show also investigates a dramatic volcanic eruption in Ethiopia’s Afar Depression, linked to deep crustal processes and rift dynamics. A key theme is how early successes in highly specialized gene therapies are shaping broader clinical and regulatory pathways while advanced telescopes and volcanic monitoring push our understanding of the universe and Earth’s interior.

Gene Therapy: From Ashanti to Oliver

The programme revisits the story of Ashanti da Silva, now grown and working as a genetic counsellor, and explains how the 1990 ADA skid case catalyzed the development of gene therapies. Claire Booth of Great Ormond Street Hospital outlines two broad approaches: in vivo therapies that modify genes inside the body and ex vivo therapies that modify cells outside the body before returning them to the patient. A key technique uses viral vectors to deliver a working gene, turning a defective system into a factory that produces the missing enzyme. The discussion covers why traditional gene therapies can correct many mutations, whereas gene editing tools like CRISPR-Cas systems require patient-specific mutations to be targeted. A pivotal moment is moving toward platform approaches that reuse tools and knowledge from one mutation to treat others more quickly and safely, with regulators gradually embracing these advances as safe and effective. "Gene therapy is modifying a person's genes to treat or cure disease" - Claire Booth, professor in gene therapy at Great Ormond Street Hospital.

Brain White Matter: Four Turning Points

New Scientist’s Penny Sarchet summarises a study mapping white matter aging from birth to 90, identifying four major phases. Cables lengthen and become more intricate in early life, then shorten and optimize through adulthood, stabilize into midlife with slight efficiency losses, and finally show increased disconnection in old age, with information rerouted through hubs. The discussion ties these changes to dementia risk around 65 and notes that grey matter remodelling largely completes by the early twenties, explaining teen decision-making patterns. These findings illuminate how brain architecture evolves across the lifespan and what that means for aging populations and cognitive health. "There are four main changes in white matter tracks across the lifetime" - Penny Sarchet, New Scientist.

The Cosmos and a Shuttered Giant: A Telescope’s Farewell

Dr Jennifer Millard explains why the Atacama Cosmology Telescope is retiring after a 13 billion-year data haul that mapped the cosmic microwave background. The CMB encodes information about the early universe and the expansion rate, offering clues that reveal tensions with local measurements of the Hubble constant. The discussion also contrasts the Chilean high-altitude site with new facilities like the Simons Observatory, designed to upgrade resolution and enable cross-scale observations. The move from an advanced, ageing instrument to a modern, multi-telescope ensemble signals ongoing progress in cosmology and instrumentation. "Old telescopes have been observing the oldest light in the universe" - Dr Jennifer Millard.

Volcanology in Afar: Rift Dynamics and a Violent Eruption

Roland Pease introduces a dramatic eruption in the Afar Depression, linked to a dike intrusion that injected magma into a shallow chamber beneath Haligubi. Volcanologist Carolina Pagli describes how magma moving through cracks and interacting with the chamber triggered rapid, explosive activity, with surface degassing and ground deformation signaling the unsettled subsurface. The region’s tectonics are part of Africa’s rifting process, with plate motions around 2 centimeters per year and a history of slow build-up that can suddenly produce rapid, kilometres-long magma movement and eruptive episodes. The segment connects these processes to broader questions about Earth’s geology and the region’s fossil heritage. "Magma intruded into a crack that intersected the Haligubi magma chamber, leading to a large eruption" - Carolina Pagli, volcanologist.

Golden Retrievers and Cross-Species Genetics

Penny Sarchet highlights a large dog-genetics study that links 12 genes in golden retrievers to similar behavioural patterns in humans, including social anxiety and trainability. The discussion emphasises that no single gene determines behavior, but that certain variants can influence tendencies across mammals. This cross-species insight suggests shared biological templates that shape behavior and cognition, while underscoring the complexity of interpreting genetic contributions to complex traits. "12 of the genes that seem linked to golden retriever behaviours are also linked to different kinds of behaviour in humans" - Penny Sarchet, New Scientist.

Overall the episode traces how breakthroughs in gene therapy, insights into brain aging, and advances in space and Earth science reflect an ongoing scientific journey from rare-case achievements toward broader understanding and application, with a future that regulators and researchers are actively shaping.