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

Vascular Spasm01:16

Vascular Spasm

1.9K
The vascular phase, also known as vasospasm, is the initial stage of hemostasis, crucial for preventing excessive bleeding when a blood vessel is injured. After a vessel is cut, nerves in the damaged area trigger pain and other sensory impulses. Simultaneously, the smooth muscles in the vessel wall contract, resulting in a vascular spasm. This contraction reduces the vessel's diameter at the injury site, slowing or stopping blood loss through the vessel wall. Vascular spasms typically last...
1.9K
Hypersensitivities01:30

Hypersensitivities

1.1K
Hypersensitivity, also known as a hypersensitivity reaction or allergic reaction, is a condition where the body's immune system reacts abnormally to a foreign substance. Such substances, that cause hypersensitivity are referred to as an allergen, could be something typically harmless to most people, like pollen or certain foods.
Types of Hypersensitivities
Hypersensitivity reactions are categorized into four types: Type 1, Type 2, Type 3, and Type 4. Each type has a distinct mechanism...
1.1K
Sympathetic Pathways: Sympathetic Chain Ganglia01:20

Sympathetic Pathways: Sympathetic Chain Ganglia

3.5K
The sympathetic chain ganglia, also known as the sympathetic trunk ganglia or paravertebral ganglia, are a series of ganglia located bilaterally on either side of the spinal column. These ganglia serve as relay stations for the sympathetic nervous system. Preganglionic neurons originating in the spinal cord project their axons to the sympathetic chain ganglia. Within the ganglia, these preganglionic fibers synapse with postganglionic neurons.The postganglionic neurons of the sympathetic trunk...
3.5K
Mitral Stenosis I: Introduction01:22

Mitral Stenosis I: Introduction

50
Mitral Valve Stenosis (MVS) is a heart condition where the mitral valve narrows, impeding blood circulation from the left atrium to the left ventricle. The etiology and pathophysiology of this condition are multifaceted, leading to a cascade of cardiovascular complications.Causes of Mitral Valve StenosisRheumatic Heart Disease: It is the main cause of mitral valve stenosis, particularly in developing nations. This condition arises from rheumatic fever, an inflammatory illness resulting from...
50
Visual Agnosia01:12

Visual Agnosia

330
Visual agnosia is a condition characterized by the inability to recognize visually presented objects despite having normal vision. For instance, a person with visual agnosia can describe the shape and color of an object but cannot identify or name it. This impairment does not affect their visual field, acuity, color vision, brightness discrimination, language, or memory. An example of this condition in a social setting is someone at a dinner party asking for "that silver thing with a round...
330
Mitral Stenosis II: Clinical features and Diagnostic Tests01:23

Mitral Stenosis II: Clinical features and Diagnostic Tests

39
Mitral stenosis is a heart condition in which the mitral valve, which allows blood to flow from the left atrium to the left ventricle, becomes narrowed or stenotic. This narrowing hinders blood flow and leads to clinical symptoms requiring specific medical evaluations and management strategies. The following overview outlines the clinical symptoms, assessments, diagnostic findings, prevention methods, and treatments for mitral stenosis.Clinical ManifestationsDyspnea (shortness of breath): This...
39

You might also read

Related Articles

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

Sort by
Same author

Leveraging Next-Generation Phenotyping in Dysmorphology to Support Variant Interpretation in Mowat-Wilson Syndrome.

Neurology. Genetics·2026
Same author

Comprehensive Assessment of the KDM2B-Associated Neurodevelopmental Disorder and the 12q24.31 Microdeletion Syndrome.

Clinical genetics·2026
Same author

Investigating the neuronal role of the proteasomal ATPase subunit gene PSMC5 in neurodevelopmental proteasomopathies.

Nature communications·2025
Same author

Author Correction: Next-generation phenotyping integrated in a national framework for patients with ultrarare disorders improves genetic diagnostics and yields new molecular findings.

Nature genetics·2025
Same author

<i>LSM1</i> c.231+4A>C hotspot variant is associated with a novel neurodevelopmental syndrome: first patient cohort.

Journal of medical genetics·2025
Same author

GestaltGAN: synthetic photorealistic portraits of individuals with rare genetic disorders.

European journal of human genetics : EJHG·2025

Related Experiment Video

Updated: Sep 18, 2025

Detection of In Situ Protein-protein Complexes at the Drosophila Larval Neuromuscular Junction Using Proximity Ligation Assay
10:31

Detection of In Situ Protein-protein Complexes at the Drosophila Larval Neuromuscular Junction Using Proximity Ligation Assay

Published on: January 20, 2015

13.2K

Houge-Janssens syndrome.

Gunnar Douzgos Houge1, Sofia Douzgou Houge2, Tzung-Chien Hsieh3

  • 1Department of Medical Genetics, Haukeland University Hospital, Bergen, Norway. gunnar.houge@helse-bergen.no.

European Journal of Human Genetics : EJHG
|June 24, 2025
PubMed
Summary

Houge-Janssens syndrome (HJS) results from protein phosphatase type 2A (PP2A) dysfunction, causing neurodevelopmental delays and seizures. This review explores HJS subtypes, focusing on PP2A

More Related Videos

Testing of all Six Semicircular Canals with Video Head Impulse Test Systems
08:38

Testing of all Six Semicircular Canals with Video Head Impulse Test Systems

Published on: April 18, 2019

31.1K
Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss
09:44

Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss

Published on: January 25, 2016

19.4K

Related Experiment Videos

Last Updated: Sep 18, 2025

Detection of In Situ Protein-protein Complexes at the Drosophila Larval Neuromuscular Junction Using Proximity Ligation Assay
10:31

Detection of In Situ Protein-protein Complexes at the Drosophila Larval Neuromuscular Junction Using Proximity Ligation Assay

Published on: January 20, 2015

13.2K
Testing of all Six Semicircular Canals with Video Head Impulse Test Systems
08:38

Testing of all Six Semicircular Canals with Video Head Impulse Test Systems

Published on: April 18, 2019

31.1K
Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss
09:44

Neuro-rehabilitation Approach for Sudden Sensorineural Hearing Loss

Published on: January 25, 2016

19.4K

Area of Science:

  • Genetics
  • Molecular Biology
  • Neuroscience

Background:

  • Houge-Janssens syndrome (HJS) is a genetic disorder linked to protein phosphatase type 2A (PP2A) dysfunction.
  • Core features include neurodevelopmental delay, hypotonia, seizures, and behavioral issues.
  • PP2A counteracts kinases in growth-promoting pathways like PIK3CA/AKT/mTOR and RAS/MAPK.

Purpose of the Study:

  • To review the clinical spectrum of HJS.
  • To elucidate known and potential pathogenic mechanisms underlying HJS.
  • To explain the biochemical and clinical overlap between different HJS subtypes.

Main Methods:

  • Literature review of clinical and genetic data.
  • Analysis of PP2A function and its role in cellular signaling pathways.
  • Examination of pathogenic variants in PP2A subunits (PPP2R5D, PPP2R5C, PPP2R1A, PPP2CA).

Main Results:

  • Pathogenic variants in PP2A subunits PPP2R5D (HJS type 1), PPP2R5C (HJS type 4), PPP2R1A (HJS type 2), and PPP2CA (HJS type 3) cause HJS.
  • Decreased PP2A activity can promote growth, potentially leading to macrocephaly or cancer.
  • Significant overlap exists between HJS subtypes, suggesting shared underlying mechanisms.

Conclusions:

  • Understanding PP2A dysfunction is crucial for HJS diagnosis and management.
  • Further research is needed to fully resolve PP2A substrate specificity and activity.
  • Potential therapeutic strategies may involve small molecules targeting PP2A activity or subunit interactions.