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In 2025 a baby in Philadelphia, known as KJ, became the first person to receive a gene-editing treatment made just for him, designed to correct the single genetic error behind his rare inherited disease.

New England Journal of Medicine (2025)

HealthScience

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KJ Muldoon was born in August 2024 with severe CPS1 deficiency: his liver lacked an enzyme needed to turn ammonia, a toxic by-product of digesting protein, into harmless urea, and the build-up can damage the brain. He was too young for a liver transplant. Doctors at Children's Hospital of Philadelphia and Penn Medicine used base editing, a refined form of the CRISPR technique that changes a single DNA letter instead of cutting through the DNA, and designed a treatment for his exact mutation in about six months. He received the first dose on 25 February 2025 and went home in June, eating more protein and needing less medicine. He is not cured, but the danger has greatly eased.

Türkçe oku
Philadelphia'da KJ adıyla bilinen bir bebek, 2025'te yalnızca kendisi için hazırlanmış bir gen düzenleme tedavisi alan ilk insan oldu. Tedavi, nadir görülen kalıtsal hastalığına yol açan tek bir genetik hatayı düzeltmek için tasarlandı.
New England Journal of Medicine (2025)

KJ Muldoon, Ağustos 2024'te ağır CPS1 eksikliğiyle doğdu. Bu hastalıkta karaciğerde, proteinlerin sindiriminden çıkan zehirli amonyağı zararsız üreye çeviren bir enzim eksiktir; biriken amonyak beyne zarar verebilir. KJ karaciğer nakli için de çok küçüktü. Philadelphia Çocuk Hastanesi ile Penn Medicine'deki doktorlar, CRISPR tekniğinin daha ince bir biçimi olan baz düzenlemeyi kullandı: Bu yöntem DNA'yı kesmek yerine tek bir harfini değiştirir. KJ'nin mutasyonuna özel tedaviyi yaklaşık altı ayda tasarladılar ve ilk dozu 25 Şubat 2025'te verdiler. Haziranda evine dönen KJ artık daha fazla protein yiyebiliyor ve daha az ilaca ihtiyaç duyuyor. Tamamen iyileşmiş değil, ama tehlike büyük ölçüde azaldı.

Sources and further reading

Background reading: CRISPR gene editing
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