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CRISPR In Vivo vs. In Vitro – What’s the Difference?

In vivo CRISPR treatment occurs inside the patient’s body, while in vitro means the editing happens outside the body, typically in a lab. In a groundbreaking, world-first in vivo CRISPR therapy, a newborn named KJ at Children’s Hospital of Philadelphia (CHOP) received a personalized gene-editing treatment for a rare and deadly genetic disorder known as CPS1 deficiency. The disease affects the urea cycle, causing dangerous ammonia buildup in the blood. Without treatment, KJ had slim chances of survival or living a normal life. Doctors at CHOP and Penn Medicine administered the treatment between 6 and 7 months of age, using lipid nanoparticles to deliver mRNA and guide RNA directly into KJ’s body—a technique never before attempted in a human, let alone an infant. KJ’s parents did not know about the condition during pregnancy—it was discovered shortly after birth. This complex and historic intervention is a massive leap for genetic medicine, previously used in in vitro contexts or for adult cases. This method has treated cancers and blood disorders, but this marks the first time a living newborn was treated internally using CRISPR, potentially opening the door for thousands of future Philadelphia birth defect treatments.

Philadelphia Birth Injury Lawyers Appreciate Breakthrough Gene Therapy at CHOP

As dedicated Philadelphia medical malpractice and Philadelphia birth injury lawyers, we stay informed about emerging medical breakthroughs that may impact the families we serve. That’s why we are incredibly proud that the world’s first in vivo CRISPR gene therapy was performed right here in Philadelphia, at Children’s Hospital of Philadelphia (CHOP).

The patient, an infant named KJ, was diagnosed after birth with severe carbamoyl phosphate synthetase 1 (CPS1) deficiency, a rare but fatal genetic disorder that blocks the body’s ability to remove excess nitrogen. KJ’s parents were unaware of the condition during pregnancy—it was discovered after birth when KJ began showing signs of toxic ammonia accumulation such as lethargy and vomiting.

CHOP’s team, collaborating with Penn Medicine, chose a revolutionary therapy: a personalized CRISPR-Cas9 gene-editing treatment. Delivered via lipid nanoparticles, this groundbreaking intervention used messenger RNA (mRNA) to program KJ’s body to correct the defective gene. This treatment has been researched in relation to cancers and genetic blood diseases like sickle cell, but KJ’s case marks the first time it has been applied directly inside a human body—especially in a newborn.

We know this therapy holds promise for families devastated by Philadelphia cancer misdiagnosis, as well as future cases involving Philadelphia birth injuries and congenital genetic disorders. Treatments like this could offer new hope to patients who previously had none.

 

Understanding Philadelphia Birth Injuries and Genetic Disorders: When Something Goes Wrong

Welcoming a new baby should be a time of joy. But when Philadelphia birth injuries or genetic disorders emerge, the emotional toll can be crushing. Families may face the devastating news that their child may not survive or may require lifelong care—something no parent ever prepares for.

Whether the problem is due to a chromosomal abnormality, a congenital metabolic disorder, or an undetected infection during pregnancy, the shock of diagnosis is often followed by a financial and emotional crisis. The reality may involve 24/7 caregiving, specialized medical equipment, ongoing physical therapy, and the loss of income when a parent stays home to provide care.

We help parents pursue justice through a Philadelphia birth injury lawsuit, recovering compensation to fund these lifelong needs. Too often, obstetricians, radiologists, and neonatal care teams miss crucial warning signs—like abnormal ultrasounds, maternal infections, or genetic predispositions—that could have prompted earlier diagnosis or intervention. Worse, patients struggling with infertility are sometimes never advised to pursue genetic testing before IVF or conception.

Medical negligence can rob a child of a healthy start. But hope is growing. With advances like gene editing and personalized mRNA-based therapies, we believe new treatments will emerge to help undo or mitigate the harm caused by medical error. In fact, gene-targeted therapies have already shown promise treating diseases like Duchenne muscular dystrophy, spinal muscular atrophy, and cystic fibrosis—disorders that were previously terminal or untreatable.

Even when a genetic defect is only discovered months or years after birth, parents may still pursue legal action thanks to the “discovery rule”. In Pennsylvania, while the general statute of limitations for medical malpractice is two years, that time may begin when the family first learns of the defect and its likely medical cause—not the date of birth. This legal nuance is essential for families who never received the truth during pregnancy. While we do not know the specific details of the pregnancy, doctor’s appointments, ultrasounds, or prenatal testing in little KJ’s case, we want parents in Philadelphia and beyond to understand that, in general, the misdiagnosis of a fetus’s condition—such as genetic mutations, birth defects, or other serious abnormalities—may be grounds for a medical malpractice lawsuit and potential compensation.

 

Can CRISPR Help Cancer Patients? The Promise of Gene Editing After Misdiagnosis

According to the National Cancer Institute (NCI) and the National Institutes of Health (NIH), CRISPR technology is revolutionizing cancer research and treatment—and below, we’ll explain exactly how it’s making that transformation possible. 

Is CRISPR cancer treatment more or less aggressive than chemotherapy or radiation?
In many cases, CRISPR-based treatments are less aggressive, targeting only the mutated genes without affecting healthy cells—unlike chemotherapy and radiation, which destroy both healthy and cancerous tissue.

This is critical for patients who were victims of Philadelphia cancer misdiagnosis and lost the window for early, curable treatment. For them, gene editing may offer one final chance at remission. Clinical trials have already shown CRISPR’s potential in treating leukemia, lymphoma, and some lung and colon cancers. By correcting genetic mutations at the root cause, CRISPR may supplement toxic treatments or eventually replace them altogether.

Unfortunately, standard treatments like chemotherapy still carry well-known risks—hair loss, infections, organ damage—but also catastrophic dangers when improperly administered. Philadelphia chemotherapy overdoses can lead to wrongful death if patients receive dangerously high doses. This underscores how even standard care can be deadly when providers are negligent.

Gene therapy may become the standard of care in the future, but for now, it remains limited by regulatory approvals, high costs, and technical challenges. However, each successful case, like that of KJ’s, shows we’re closer to a day when patients—especially those harmed by Philadelphia medical malpractice and birth injury —may benefit from safer, targeted options.

 

Gene-Targeted Therapies: Which Conditions Could Be Cured Next?

What diseases can gene-targeted CRISPR therapies treat?
Gene therapies, especially CRISPR-based ones, are already being tested or used for:

• Cystic fibrosis 
• Sickle cell anemia 
• Beta thalassemia 
• Duchenne muscular dystrophy 
• Certain cancers 
• Inherited blindness (Leber congenital amaurosis) 
• Neurological disorders like Huntington’s 

In neonatology, promising candidates include Tay-Sachs, Spinal Muscular Atrophy (SMA), and Fragile X syndrome—some detectable during pregnancy, others after birth when developmental milestones are missed.

Will it someday be possible to cure all newborn conditions with gene-targeting therapies?

Not all children with genetic disorders will qualify, but as research expands, we expect more personalized, in vivo therapies to be accessible. In time, even complex chromosomal abnormalities like Trisomy 13 or 18, or rare metabolic conditions like Maple Syrup Urine Disease, may become treatable at the gene level.

Summary: A Breakthrough in Genetic Medicine at CHOP

CHOP’s bold decision to deliver the first-ever in vivo CRISPR therapy to a newborn was a historic medical moment. With precise delivery of gene-editing tools inside the body, KJ’s CPS1 deficiency was treated at the root, not just managed with drugs. This tiny patient has the potential to lead a normal life thanks to the bravery of physicians willing to challenge the status quo.

CHOP and Penn Medicine – Leading the Future of Neonatology and Precision Medicine

As Philadelphia birth trauma and medical malpractice lawyers, we typically fight to hold negligent doctors accountable. But today, we commend the teams at CHOP and Penn Medicine for leading the future of neonatology and precision medicine. Their innovation offers a brighter path forward for countless children, especially those who might otherwise suffer lifelong disabilities due to genetic errors or Philadelphia birth injuries.

We’ll continue to advocate for justice and accountability—but also for the healthcare advancements that offer real hope to the families we serve.

Contact a Philadelphia Medical Malpractice Attorney

If your child was born with a Philadelphia birth defect, or you suspect medical error played a role in their condition, don’t wait. Call our experienced Philadelphia birth defect lawyers or schedule a free consultation with a Philadelphia medical malpractice attorney today. Your window for justice may be limited—but your child’s future doesn’t have to be. Call (610) 351 – 2330 to meet Philadelphia medical malpractice and personal injury lawyer near you!

 

 

Last Updated on June 19, 2025