J Mov Disord.  2017 Jan;10(1):53-58. 10.14802/jmd.16044.

Familiar Hyperekplexia, a Potential Cause of Cautious Gait: A New Korean Case and a Systematic Review of Phenotypes

• Lee Y
• Kim NY
• Hong S
• Chung SJ
• Jeong SH
• Lee PH
• Sohn YH

• KMID: 2367609
• DOI: http://doi.org/10.14802/jmd.16044

Abstract

Familial hyperekplexia, also called startle disease, is a rare neurological disorder characterized by excessive startle responses to noise or touch. It can be associated with serious injury from frequent falls, apnea spells, and aspiration pneumonia. Familial hyperekplexia has a heterogeneous genetic background with several identified causative genes; it demonstrates both dominant and recessive inheritance in the α1 subunit of the glycine receptor (GLRA1), the β subunit of the glycine receptor and the presynaptic sodium and chloride-dependent glycine transporter 2 genes. Clonazepam is an effective medical treatment for hyperekplexia. Here, we report genetically confirmed familial hyperekplexia patients presenting early adult cautious gait. Additionally, we review clinical features, mode of inheritance, ethnicity and the types and locations of mutations of previously reported hyperekplexia cases with a GLRA1 gene mutation.

Keyword

Hyperekplexia; GLRA1; deep phenotyping

MeSH Terms

Accidental Falls
Adult
Apnea
Clonazepam
Gait*
Genetic Background
Glycine Plasma Membrane Transport Proteins
Humans
Nervous System Diseases
Noise
Phenotype*
Pneumonia, Aspiration
Receptors, Glycine
Reflex, Startle
Sodium
Stiff-Person Syndrome*
Wills
Clonazepam
Glycine Plasma Membrane Transport Proteins
Receptors, Glycine
Sodium