Hyperekplexia Precision Panel – 18 genes

Overview

• Hyperekplexia, also known as stiff baby syndrome or startle disease, is a rare hereditary neurological disease associated to a variety of gene mutations that affect the glycine receptor. This disorder is characterized by a triad of generalized stiffness while awake, nocturnal myoclonus and exaggerated startle reflex. These features often appear at birth alongside episodes of hypertonia or tonic spasms upon awakening. When severe, it may interfere with breathing causing irreversible brain damage. Hyperekplexia is usually misdiagnosed as a form epilepsy. It is inherited mostly as an autosomal dominant trait but can also follow autosomal recessive or X-linked inheritance. 

• The Igenomix Hyperekplexia Precision Panel  can serve as an accurate and directed diagnostic tool as well as a differential diagnosis of seizures ultimately leading to a better management and prognosis of the disease. It provides a comprehensive analysis of the genes involved in this disease using next-generation sequencing (NGS) to fully understand the spectrum of relevant genes involved.

Indication

• The Igenomix Hyperekplexia Precision Panel is indicated in patients with a clinical suspicion or diagnosis presenting with or without the following manifestations: 
  • Arching of the head alongside the startle reaction 
  • Jerking movements after startle reaction 
  • Severe muscle tension 
  • Lack of movement or slower than normal 
  • Overactive reflexes 
  • Intermittent apnea 
  • Unsteady gait 

Clinical Utility

The clinical utility of this panel is: 

• The genetic and molecular diagnosis for an accurate clinical diagnosis of a symptomatic patient.    
• Early initiation of treatment with a multidisciplinary team in the form of pharmacologic therapy with antiepileptic drugs such as clonazepam. 
• Risk assessment and genetic counselling of asymptomatic family members according to the mode of inheritance. 
• Improvement of delineation of genotype-phenotype correlation.

Genes & Diseases

* Inheritance: AD: Autosomal Dominant; AR: Autosomal Recessive; X: X linked; XLR: X linked Recessive; Mi: Mitochondrial; Mu: Multifactorial; G: Gonosomal Inheritance; D: Digenic Inheritance 

** HGMD: Number of clinically relevant mutations according to HGMD