Huntington’s disease is a fatal condition involving the death of brain cells, typically striking in midlife. But new findings suggest the disease process starts decades earlier. Although symptoms emerge in adulthood, researchers have been able to detect the earliest effects of Huntington’s in the first two weeks of human embryonic development. The findings recast Huntington’s, often considered a neurodegenerative condition, as a developmental disease, and point to new approaches for finding treatments for a disease that currently has no cure or therapies. “When the patient goes to the doctor, that’s when the last dominoes have fallen. But the first domino is pushed in the developmental phase,” says Ali Brivanlou, PhD, Head of the Laboratory of Synthetic Embryology at Rockefeller University, who, with colleagues, published the new findings in Development on October 5, 2021. “Knowing this trajectory, we may be able to block the progression of the disease,” Dr. Brivanlou. The open-access article is titled “Huntingtin CAG Expansion Impairs Germ Layer Patterning in Synthetic Human 2D Gastruloids Through Polarity Defects.”