Huntington’s Disease Research Offers New Hope for Treatment

Huntington’s disease (HD), a progressive and inherited neurological disorder, has long been regarded as incurable. Affecting movement, cognition, and emotional regulation, the condition is usually diagnosed between the ages of 30 and 50, with patients typically surviving 15–20 years after diagnosis. Although rarer than Alzheimer’s disease, HD has a profound social impact because it strikes during prime working and family-raising years. New research, however, is beginning to reshape prospects for treatment.

Genetic Basis and Disease Progression

HD is caused by an abnormal expansion of CAG DNA repeats in the Huntingtin (HTT) gene, first identified in 1993. Healthy individuals have fewer than 35 repeats, while counts above 39 inevitably lead to HD. Longer repeats are associated with earlier symptom onset. Beyond inheritance, the repeat length can further expand in certain cells over a lifetime, a process known as somatic expansion, which influences how rapidly the disease progresses.

Early Brain Changes Before Symptoms

Research has shown that brain changes occur decades before visible movement problems appear. The earliest damage is seen in the striatum, a brain region crucial for motor control, where specific neurons gradually die. As the disease advances, degeneration spreads to the cortex and white matter, affecting cognition and emotional processing. Subtle impairments in attention, mood, and cognitive flexibility have been detected many years before diagnosis.

Breakthroughs in Gene Therapy

Recent clinical work led by researchers at University College London has reported promising results from a gene therapy known as AMT-130. The therapy reduces production of the toxic mutant huntingtin protein. In a small trial involving clinically diagnosed patients, participants showed slower cognitive decline and reduced levels of neurofilament light, a marker of neurodegeneration, over three years. These findings suggest the therapy may protect brain cells rather than merely easing symptoms.

Imporatnt Facts for Exams

• Huntington’s disease is caused by CAG repeat expansion in the HTT gene.
• Repeat length above 39 invariably leads to disease development.
• The striatum is the earliest brain region affected in HD.
• Somatic expansion influences disease onset and progression.

Early Detection and Future Treatment Window

Long-term studies of individuals carrying the HD gene expansion, conducted decades before expected symptom onset, have identified early markers of neurodegeneration and attention deficits. These findings indicate a potential treatment window long before motor symptoms emerge. As disease-modifying therapies advance, early intervention could preserve cognitive function, improve quality of life, and possibly extend lifespan, marking a significant shift in the outlook for people with Huntington’s disease.