{"id":338776,"date":"2025-12-09T10:34:36","date_gmt":"2025-12-09T10:34:36","guid":{"rendered":"https:\/\/www.newsbeep.com\/us\/338776\/"},"modified":"2025-12-09T10:34:36","modified_gmt":"2025-12-09T10:34:36","slug":"the-baby-whose-life-was-saved-by-the-first-personalized-crispr-therapy","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/us\/338776\/","title":{"rendered":"The baby whose life was saved by the first personalized CRISPR therapy"},"content":{"rendered":"

\n You have full access to this article via your institution.<\/p>\n

To the research team working to save him, KJ Muldoon was first known only as Patient Eta.<\/p>\n

But within months, KJ\u2019s name \u2014 and megawatt, chubby-cheeked smile \u2014 would be splashed across newspapers and broadcasts around the world as the first known person to receive a personalized CRISPR-based genome-editing therapy<\/a>.<\/p>\n<\/p>\n

Soon after KJ was born in August 2024, doctors noticed that he was sleeping too much and eating too little. After a bevy of tests, they found that KJ has an ultra-rare genetic condition, called carbamoyl-phosphate synthetase 1 (CPS1) deficiency, that impairs the body\u2019s ability to process protein.<\/p>\n

When the body breaks down proteins, it produces ammonia \u2014 a toxic substance that is usually processed by enzymes in the liver and excreted in urine. CPS1 deficiency compromises one of these enzymes, causing ammonia to accumulate in the blood, which can eventually damage the brain. The condition can be treated with a liver transplant, but about half of all babies with CPS1 deficiency die in early infancy.<\/p>\n

One of KJ\u2019s doctors, paediatrician Rebecca Ahrens-Nicklas at the Children\u2019s Hospital of Philadelphia in Pennsylvania, wondered whether there might be another solution \u2014 correcting the faulty enzyme in his liver. She and Kiran Musunuru, a cardiologist at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, had a bold plan to treat children with rare genetic disorders using gene-editing therapies tailored to unique DNA sequences<\/a>. KJ could be their first candidate.<\/p>\n

Previous gene-editing therapies were designed to treat many people. The first approved CRISPR therapy, called Casgevy, could potentially treat tens of thousands of people with one of two blood disorders. By contrast, KJ\u2019s therapy would work only for him.<\/p>\n

The team used an offshoot of CRISPR genome editing, called base editing, to target the problematic mutation \u2014 one faulty DNA letter out of the three billion in the human genome \u2014 and correct it (K. Musunuru et al. N. Engl. J. Med. 392, 2235\u20132243; 2025<\/a>). Such a hyper-personalized editing therapy had never been made so quickly; KJ might only have a few months before ammonia overwhelmed his small body.<\/p>\n

In the end, it took a large team of researchers in academia and industry to make it happen. While KJ charmed everyone he met at the hospital, Musunuru and his lab members shielded themselves from learning any personal details about him, even his name. \u201cThere were certain go or no-go points where key decisions had to be made,\u201d Musunuru says. \u201cWe had to be objective with respect to the data.\u201d<\/p>\n

Manufacturing companies worked around the clock to make the gene-editing components needed to treat KJ. \u201cWe estimated that it would take 18 months,\u201d says Sandy Ottensmann, a vice-president at Integrated DNA Technologies in Coralville, Iowa. \u201cWe did it in six.\u201d<\/p>\n

On 25 February, KJ received the first of three infusions. His tolerance for protein in his diet has increased, but he still needs medication and regular monitoring to ensure that his ammonia levels stay in check.<\/p>\n

After spending the first 307 days of his life in the hospital, KJ went home in June. As he left, hospital workers lined the hallways and the road outside, clapping. At home, KJ continued to hit his developmental milestones: eating solids and working towards taking his first steps. \u201cHe\u2019s always smiling,\u201d says his mother, Nicole Aaron.<\/p>\n

The question now is how to ensure that other children will have the same opportunity. It costs millions of dollars to treat one person with Casgevy, and investors have been shying away from genome-editing companies. Several firms have laid off staff and discontinued programmes. \u201cNow it seems to come down, a lot of times, just to the money,\u201d says Joseph Hacia, a medical geneticist at the Keck School of Medicine at the University of Southern California in Los Angeles. But there is fresh hope, he says: two programmes announced by the US Advanced Research Projects Agency for Health aim to bring \u201cprecision genetic medicines\u201d to people with rare diseases.<\/p>\n

Ahrens-Nicklas and Musunuru have been crafting a clinical trial<\/a> of their approach in more children \u2014 as quickly as they can, says Ahrens-Nicklas. \u201cEveryone saw the possibility and thought, \u2018Why isn\u2019t this available for my child?\u2019\u201d<\/p><\/p>\n","protected":false},"excerpt":{"rendered":"You have full access to this article via your institution. To the research team working to save him,…\n","protected":false},"author":2,"featured_media":338777,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[34],"tags":[126735,13056,97,1159,10545,1160,79],"class_list":{"0":"post-338776","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-health","8":"tag-crispr-cas9-genome-editing","9":"tag-gene-therapy","10":"tag-health","11":"tag-humanities-and-social-sciences","12":"tag-medical-research","13":"tag-multidisciplinary","14":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/338776","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/comments?post=338776"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/posts\/338776\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media\/338777"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/media?parent=338776"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/categories?post=338776"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/us\/wp-json\/wp\/v2\/tags?post=338776"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}