Three Years of Struggle: 3-Year-Old Girl Gets a Chance at Normal Development Thanks to Gene Therapy

Texas Children’s Hospital has become the first in the world to use gene therapy to treat a three-year-old girl with aromatic L-amino acid decarboxylase (AADC) deficiency—a rare inherited neurological disorder, reports Medical Xpress.

This condition prevents the brain from producing dopamine and serotonin—neurotransmitters essential for movement, mood regulation, and various nervous system functions. Only around 350 cases have been documented worldwide, and without treatment, life expectancy is typically limited to five to seven years.

In November 2024, the U.S. approved Kebilidi (eladocagene exuparvovec-tneq), a gene therapy based on adeno-associated virus type 2. The treatment is delivered by a neurosurgeon directly into the brain’s putamen region. The procedure takes about six hours and involves four infusions during a single operation.

The three-year-old patient began showing signs of developmental delay at just seven months—poor muscle control, trouble holding up her head, and other classic symptoms of AADC deficiency. Genetic testing confirmed the diagnosis at 18 months. Before the gene therapy, she received medication and physical therapy, but with minimal progress.

Dr. Daniel Curry, neurosurgeon and director of the Center for Functional Neurosurgery at Texas Children’s Hospital, emphasized that AADC deficiency was once considered a hopeless diagnosis. This new therapy, he said, marks the beginning of an era where previously untreatable genetic conditions can now be addressed.

Texas Children’s Hospital played a leading role in the clinical trial that led to the approval of Kebilidi. This breakthrough offers hope for treating other rare inherited diseases in children.

The case of this young girl demonstrates how molecular medicine is transforming lives, offering families hope and paving the way for new therapeutic possibilities in genetic medicine.