We report sleep phenotypes and polysomnographic findings in two siblings with a novel homozygous variant of the GLRA1 gene causing hereditary hyperekplexia (HH).
The pathogenesis of hereditary hyperekplexia is thought to involve abnormalities in the glycinergic neurotransmission system, the most of mutations reported in GLRA1.
Six patients with hereditary hyperekplexia (HH) and a confirmed mutation in the gene encoding the alpha(1) subunit of the glycine receptor (GLRA1) underwent single voxel (1)H magnetic resonance spectroscopy (MRS) of the brainstem and an area of frontal cortex and white matter using a method that allows absolute quantification of metabolites.
Hereditary hyperekplexia is a dominant neurological disorder associated with point mutations at the channel-forming segment M2 of the glycine receptor alpha 1 subunit.
This study presents a large family with HH as a result of homozygous mutation in GLRB and expands the clinical spectrum of HH to include eye misalignment disorder.