Hyperekplexia : Adaptative Skills and Neurodevelopmental Trajectory

Last updated: May 30, 2024
Sponsor: Hospices Civils de Lyon
Overall Status: Active - Recruiting

Phase

N/A

Condition

N/A

Treatment

collection of medical data

Vineland Adaptive Behaviour Scales (VABS2) questionnaire

Clinical Study ID

NCT05652101
69HCL22_0568
2022-A02107-36
  • Ages > 2
  • All Genders

Study Summary

Hereditary hyperekplexia is a rare neuronal disorder, caused by genetic defects leading to dysfunction of glycinergic neurotransmission.

The clinical presentation is characterized by stiffness and exaggerated startle responses to unexpected stimuli, that appear shortly after birth.

The generalised stiffness can lead to apnea and sudden infant death syndrome.

Several genes are known to be associated with hereditary hyperekplexia. The most frequent are Glycine Receptor Alpha 1 (GLRA1), Glycine Receptor Beta (GLRB) and Solute Carrier Family 6 Member 5 (SLC6A5). They encode for the postsynaptic glycine receptor (GLRA1, GLRB) and the presynaptic glycine transport (SLC6A5). Genetic mutations in these genes lead to dysfunction in the glycinergic inhibitory neurotransmission.

The neurodevelopment was initially described as normal, or as delayed due to the motor difficulties. Global development delay and intellectual disability are reported as well, in the most recent studies.

Nevertheless, the degree of severity of the learning difficulties and the adaptive faculties of the patients is not specified.

Similarly, the efficacy of clonazepam in hyperekplexia is well known, but the evolution of dosage over time and the frequency of complete withdrawal have never been studied.

The primary endpoint of this study is to describe adaptive skills using a standardized questionnaire, Vineland Adaptive Behavior Scale (VABS2).

Secondary endpoints are:

  • Neurodevelopmental course study

  • Description of the evolution of the clinical manifestations over the years

  • Evaluation of the efficacity of the treatment CLONAZEPAM, initially and over time, and evolution of the dosage

  • Comparison of clinical and therapeutical characteristics according to the genotype

Eligibility Criteria

Inclusion

Inclusion Criteria:

  • Clinical diagnostic criteria for hyperekplexia (see Thomas et al. BRAIN, 2013):

  • The presence of hypertonia (either hypertonia on examination, axial orsegmental, or access of stiffness)

  • Exaggerated reflex startles, to auditory, tactile or visual stimuli

  • The presence of reflex bursts on percussion of the midline

  • Children >2 years and adults

  • No opposition of one of the two parents (or legal representative) or of the adultpatient

Exclusion

Exclusion Criteria:

  • The presence of a cause secondary to the hyperekplexia (traumatic, autoimmune, etc.)

  • The presence of another cause for a delay in psychomotor development (otherneurological pathology, serious head trauma, etc.)

  • Pregnant or breastfeeding women

  • Person deprived of liberty by judicial or administrative decision

Study Design

Total Participants: 40
Treatment Group(s): 2
Primary Treatment: collection of medical data
Phase:
Study Start date:
April 24, 2023
Estimated Completion Date:
April 01, 2025

Connect with a study center

  • Hopital Femme Mère Enfant

    Bron, 69500
    France

    Active - Recruiting

Not the study for you?

Let us help you find the best match. Sign up as a volunteer and receive email notifications when clinical trials are posted in the medical category of interest to you.