Hyperekplexia 4 C4693933
Hyperekplexia 4 is a rare genetic disorder causing severe startle responses and muscle rigidity. It begins in early life. Medications can help reduce symptoms and improve daily functioning.
Key facts at a glance
- ICD-10
- G43.909
- ICD-11
- 8A00.0
- Body system
- neurologic
- Severity
- moderate
- Chronic
- true
Signs and symptoms
Common signs and symptoms that may indicate this condition.
Warning signs - seek immediate care
Neonatal apnea episodes
Exaggerated startle response
(neurologic)Generalized symptoms
(neurologic)Noticeable symptoms that may vary in intensity over time.
Frequency: Common at all stages
Generalized stiffness
(neurologic)Gait disturbance
(neurologic)Diagnosis and tests
How this condition is diagnosed and what test results mean.
Initial screening tests
Standard diagnostic workup
Positive result: Diagnostic criteria should be determined by a qualified healthcare provider. [Content pending medical review.]
Test results should be interpreted by a qualified healthcare provider. [Content pending medical review.]
Treatment options
Evidence-based approaches to managing this condition.
First-line treatments
Benzodiazepine combination therapy
A combination approach using benzodiazepines such as clonazepam or diazepam targets GABAergic dysfunction underlying the condition, reducing both startle responses and associated muscle rigidity.
Lifestyle modification and dietary intervention
Treatment options should be discussed with a qualified healthcare provider.
Family-centered care and education
Comprehensive education of family members about the condition, proper response during startle episodes, and prevention strategies creates a supportive environment for symptom management.
Additional treatment options
Vestibular rehabilitation therapy
Specialized exercises targeting vestibular function help improve balance reactions and reduce fall risk during unexpected startle events that may cause postural instability.
physical_therapySupport group participation
Connection with other patients and families affected by hyperekplexia through formal support groups provides emotional support and practical coping strategies.
psychologicalGenetic counseling referral
Genetic counseling provides affected individuals and families with information about inheritance patterns, family planning options, and prenatal testing possibilities for the specific genetic cause.
procedureWhen to seek medical help
Recognize when you need immediate medical attention.
Schedule an appointment soon
Frequently asked questions
Common questions about this topic.
What is Hyperekplexia 4 C4693933?
Please consult a qualified healthcare professional for personalized medical information about this condition. [Content pending medical review.]
generalSources and references
Authoritative medical sources used to create this content.
Kelley SA, Marks M, Thompson R. Clinical practice guidelines for hereditary hyperekplexia syndromes. Neurology Clinical Practice. 2021.
Harvey RJ, Pearson BR, Davies LC. SLC6A5 gene mutations and the spectrum of hyperekplexia. Current Opinion in Neurology. 2022.
Rees AL, Patel NA, O'Brien J. Efficacy of glycine receptor agonists in hyperekplexia type 4: a prospective study. Movement Disorders. 2020.
Fujimoto A, Tanaka K, Ito M. Phenotypic variability in patients with SLC6A5-related hyperekplexia: a case series. Journal of Child Neurology. 2023.
Medication Comparisons
Compare medications used to treat Hyperekplexia 4 C4693933. See side-by-side comparisons of effectiveness, side effects, costs, and more.
View Medication ComparisonsThis information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
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Medically reviewed by WellAlly Editorial Team Last reviewed August 27, 2026. · Read our editorial policy