NYSE:NVS News 27 June 2025 - 27 October 2025

Key facts (quick read) In‑depth report 1) Huntington’s disease, in plain English What it is. HD is a progressive brain disorder that typically begins in mid‑adulthood, causing a mix of movement (chorea, dystonia), cognitive (processing speed, executive function) and psychiatric symptoms (depression, irritability). It is uniformly fatal over years to decades.  NIH Neurological Institute+1 Genetics. HD is autosomal dominant: each child of an affected parent has a 50% chance to inherit the expansion. The disease is caused by CAG repeat expansion in HTT: ≥40 repeats almost always cause disease in a normal lifespan; 36–39 have reduced penetrance; 27–35 are intermediate (no disease in the carrier but potential expansion in offspring). Anticipation—earlier onset in successive generations—occurs, especially with paternal