Related Experiment Video
Updated: May 12, 2026
08:29
Symmetric Bihemispheric Postmortem Brain Cutting to Study Healthy and Pathological Brain Conditions in Humans
Published on: December 18, 2016
14.5K
Late-Onset Huntington's Disease in Mexico: A Retrospective Study
Adriana Ochoa-Morales1, Kerstin Beutelspacher-Fernandez1, Aurelio Jara-Prado1
1Genetics Department, National Institute of Neurology and Neurosurgery Manuel Velasco Suárez, Mexico City, MEX.
Cureus
|November 14, 2025
Summary
Late-onset Huntington's disease (LoHD) is rare, often lacking family history and presenting with motor symptoms. Further research is needed to understand factors delaying onset in these Huntington's disease patients.
Area of Science:
- Neuroscience
- Genetics
- Neurology
Background:
- Huntington's disease (HD) is a dominant neurodegenerative disorder typically starting in adulthood.
- Late-onset Huntington's disease (LoHD) is a less common form beginning after age 60.
- Understanding LoHD characteristics is crucial for diagnosis and management.
Purpose of the Study:
- To characterize the main features of LoHD patients at a leading Mexican neurological center.
- To analyze demographic, clinical, and molecular aspects of LoHD.
- To identify potential factors influencing delayed onset in Huntington's disease.
Main Methods:
- Retrospective, cross-sectional study of HD patient records from 1994 to mid-2024.
- Data collection included age, onset, diagnostic delay, family history, molecular results, and clinical presentation.
- Analysis of Unified Huntington's Disease Rating Scale-Total Motor Score (UHDRS-TMS) for motor function.
Main Results:
- 104 (7%) of 1,476 HD patients had LoHD, with 56.7% being female.
- Mean age of onset was 65.1 years, with a mean diagnostic delay of 6.2 years.
- Average CAG repeats were 41.4, and 89% presented with initial motor symptoms.
Conclusions:
- LoHD is a rare Huntington's disease variant with diverse presentations.
- A significant proportion of LoHD cases lack a family history.
- CAG repeat lengths in LoHD overlap with typical HD, necessitating research into onset modifiers.
Related Concept Videos
01:05Long-term Depression
Long-term depression, or LTD, is one of the ways by which synaptic plasticity—changes in the strength of chemical synapses—can occur in the brain. LTD is the process of synaptic weakening that occurs over time between pre and postsynaptic neuronal connections. The synaptic weakening of LTD works in opposition to synaptic strengthening by long-term potentiation (LTP) and together are the main mechanisms that underlie learning and memory.
01:29Cardiomyopathy III: Hypertrophic Cardiomyopathy
Hypertrophic cardiomyopathy, or HCM, is an autosomal dominant genetic disorder characterized by asymmetric left ventricular hypertrophy without ventricular dilation. It is more common in men and is typically diagnosed in young, athletic adults.EtiologyHCM is primarily genetic and is caused by mutations in genes encoding sarcomeric proteins. Researchers have identified over 1400 mutations across at least 11 different genes. Among these, the most frequently occurring mutations are found in the...
01:29Alzheimer Disease l: Introduction
Alzheimer disease is a chronic, progressive, and irreversible neurodegenerative disorder and the most common cause of dementia in older adults. It leads to gradual neuronal loss, causing cognitive decline, behavioral changes, and loss of functional independence.Risk Factors and EtiologyThe disease is multifactorial. Age is the strongest risk factor, with prevalence doubling every 5 years after age 65. Genetic factors include mutations in genes such as APP, PSEN1, and PSEN2, which are associated...
01:24Parkinson Disease ll: Pathophysiology
Parkinson disease (PD) is a progressive neurodegenerative disorder primarily affecting movement, with additional non-motor features. Its pathophysiology involves complex interactions among genetic susceptibility, environmental exposures, and cellular dysfunction, including dopaminergic neuron loss, protein aggregation, and mitochondrial impairment.Selective NeurodegenerationA key feature is the degeneration of dopaminergic neurons in the substantia nigra pars compacta, leading to reduced...
01:21Huntington Disease l: Introduction
Huntington disease or HD is a progressive, fatal neurodegenerative disorder inherited in an autosomal dominant pattern.PathophysiologyIt is caused by expansion of the CAG trinucleotide repeat in the HTT gene on chromosome 4 (4p16.3), producing an abnormal huntingtin protein with an expanded polyglutamine tract. This misfolded protein disrupts cellular function, leading to neuronal death. Normal alleles have ≤26 repeats, 27–35 are intermediate (risk of expansion), 36–39 show reduced penetrance,...