Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Cardiomyopathy III: Hypertrophic Cardiomyopathy01:29

Cardiomyopathy III: Hypertrophic Cardiomyopathy

17
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...
17
Genetic Lingo01:11

Genetic Lingo

103.3K
Overview
103.3K
Lysosomal Hydrolases01:22

Lysosomal Hydrolases

3.9K
Lysosomes are the site for the degradation of macromolecules and biological polymers released during membrane trafficking events such as secretory, endocytic, autophagic, and phagocytic pathways. The membrane-enclosed area of the lysosome, called the lumen, contains hydrolytic enzymes active in an acidic environment. These acid hydrolases are functional at a pH between 4.5 and 5 and are involved in cellular processes such as cell signaling, energy metabolism, restoration of the plasma membrane,...
3.9K
Genome-wide Association Studies-GWAS01:11

Genome-wide Association Studies-GWAS

13.7K
Genome-wide association studies or GWAS are used to identify whether common SNPs are associated with certain diseases. Suppose specific SNPs are more frequently observed in individuals with a particular disease than those without the disease. In that case, those SNPs are said to be associated with the disease. Chi-square analysis is performed to check the probability of the allele likely to be associated with the disease.
GWAS does not require the identification of the target gene involved in...
13.7K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Unifying Divergent Conceptions in Nonfluent/Agrammatic and Semantic Primary Progressive Aphasia.

Brain sciences·2026
Same author

A Patient-Reported Outcome Measure of Communication Difficulties in Friedreich Ataxia: COMATAX.

Cerebellum (London, England)·2026
Same author

Effect of semantic and metacognitive rehabilitation in semantic variant primary progressive aphasia: a single-case experimental study.

Annals of physical and rehabilitation medicine·2026
Same author

A Severity-Agnostic Atrophy Pattern in Spinocerebellar Ataxia Type 3: Volumetrics from ENIGMA-Ataxia.

Movement disorders : official journal of the Movement Disorder Society·2026
Same author

Cerebral Amyloid Angiopathy and Risk of Dementia in Patients With Cognitive Complaint.

Neurology·2026
Same author

Early and Progressive Spinal Cord Atrophy in Spinocerebellar Ataxia Type 1.

Movement disorders : official journal of the Movement Disorder Society·2026

Related Experiment Video

Updated: Jul 27, 2025

Efficient and Scalable Production of Full-length Human Huntingtin Variants in Mammalian Cells using a Transient Expression System
10:52

Efficient and Scalable Production of Full-length Human Huntingtin Variants in Mammalian Cells using a Transient Expression System

Published on: December 10, 2021

2.6K

Huntington's Disease with Small CAG Repeat Expansions.

Anna Heinzmann1,2, Sabrina Sayah2, François-Xavier Lejeune1,3

  • 1Sorbonne Université, Paris Brain Institute (ICM Institut du Cerveau), APHP, INSERM, CRNS, Paris, France.

Movement Disorders : Official Journal of the Movement Disorder Society
|June 8, 2023
PubMed
Summary

Individuals with small CAG repeat expansions (36-38) in the HTT gene show similar cognitive function to those with typical Huntington's disease expansions (40-42). However, they often present with fewer motor symptoms, potentially delaying diagnosis.

Keywords:
Huntington's diseasechoreacognitive declinereduced penetrancesmall expansions

More Related Videos

Measuring RAN Peptide Toxicity in C. elegans
10:49

Measuring RAN Peptide Toxicity in C. elegans

Published on: April 30, 2020

6.7K
Fractionation for Resolution of Soluble and Insoluble Huntingtin Species
07:08

Fractionation for Resolution of Soluble and Insoluble Huntingtin Species

Published on: February 27, 2018

9.6K

Related Experiment Videos

Last Updated: Jul 27, 2025

Efficient and Scalable Production of Full-length Human Huntingtin Variants in Mammalian Cells using a Transient Expression System
10:52

Efficient and Scalable Production of Full-length Human Huntingtin Variants in Mammalian Cells using a Transient Expression System

Published on: December 10, 2021

2.6K
Measuring RAN Peptide Toxicity in C. elegans
10:49

Measuring RAN Peptide Toxicity in C. elegans

Published on: April 30, 2020

6.7K
Fractionation for Resolution of Soluble and Insoluble Huntingtin Species
07:08

Fractionation for Resolution of Soluble and Insoluble Huntingtin Species

Published on: February 27, 2018

9.6K

Area of Science:

  • Genetics
  • Neuroscience
  • Neurology

Background:

  • Small cytosine-adenine-guanine (CAG) repeat expansions (36-38) in the HTT gene are traditionally linked to milder Huntington's disease (HD).
  • The clinical presentation and detailed phenotype of these individuals remain understudied.
  • Understanding their profile is crucial for accurate diagnosis and genetic counseling.

Purpose of the Study:

  • To investigate the clinical and neuropsychological phenotype of individuals carrying CAG36-38 repeat expansions in the HTT gene.
  • To compare the characteristics of CAG36-38 carriers with those of CAG40-42 carriers.
  • To elucidate factors contributing to diagnostic delays in this subgroup.

Main Methods:

  • Inclusion of 35 patients and premanifest carriers with CAG36-38 repeats.
  • Comparative analysis of clinical and neuropsychological data between 11 CAG36-38 patients and 11 matched CAG40-42 patients.
  • Utilizing data from 243 CAG36-38 individuals from the ENROLL study for comprehensive phenotype description.

Main Results:

  • Similar global cognitive efficiency and subdomain performance were observed between CAG36-38 and CAG40-42 carriers.
  • Chorea was a significantly less frequent initial symptom in CAG36-38 patients, despite comparable motor scores at initial assessment.
  • CAG36-38 carriers exhibited significantly lower total motor scores at the last visit.
  • Clinicians showed reduced confidence in diagnosing HD in CAG36-38 carriers, leading to significantly later diagnoses despite similar ages at symptom onset.
  • Confirmation of similar cognitive and distinct motor profiles in larger cohorts (CAG36-38: n=243; CAG40-42: n=4675) from the ENROLL database.

Conclusions:

  • Small CAG36-38 expansions in the HTT gene are associated with a cognitive profile similar to, but a distinct motor profile from, more common CAG40-42 expansions.
  • Absence of chorea, rather than low symptom penetrance, may contribute to delayed molecular diagnosis in CAG36-38 carriers.
  • Neurologists should consider HD in elderly patients with cognitive impairment but without typical chorea, with implications for genetic counseling of offspring.