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Hyperekplexia 1

Synonyms
GLRA1-Related Hyperekplexia; GPHN-Related Hyperekplexia; HYPEREKPLEXIA 1, AUTOSOMAL DOMINANT; HYPEREKPLEXIA 1, AUTOSOMAL RECESSIVE; Kok disease; Startle disease, familial; Startle reaction, exaggerated; Stiff-baby syndrome; Stiff-man syndrome, congenital; Stiff-person syndrome, congenital

Summary

Hyperekplexia is an early-onset neurologic disorder characterized by an exaggerated startle response to sudden, unexpected auditory or tactile stimuli. Affected individuals have brief episodes of intense, generalized hypertonia in response to stimulation. Neonates may have prolonged periods of rigidity and are at risk for sudden death from apnea or aspiration. Many affected infants have inguinal hernias. The symptoms tend to resolve after infancy, but adults may have increased startle-induced falls and/or experience nocturnal muscle jerks (summary by Ryan et al., 1992). Genetic Heterogeneity of Hyperekplexia See also HKPX2 (614619), caused by mutation in the GLRB gene (138492) on chromosome 4q31; HKPX3 (614618), caused by mutation in the GLYT2 gene (SLC6A5; 604159) on chromosome 11p15; and HKPX4 (618011), caused by mutation in the ATAD1 gene (614452) on chromosome 10q23. Hyperekplexia can also occur in developmental and epileptic encephalopathy-8 (DEE8; 300607), caused by mutation in the ARHGEF9 gene (300429). See also sporadic stiff-man syndrome (184850) and the 'Jumping Frenchmen of Maine' (244100). [from OMIM]

Available tests

43 tests are in the database for this condition.

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Clinical tests (43 available)

Molecular Genetics Tests

Genes See tests for all associated and related genes

  • Also known as: HKPX1, STHE, GLRA1
    Summary: glycine receptor alpha 1

  • Also known as: GEPH, GPH, GPHRYN, HKPX1, MOCODC, GPHN
    Summary: gephyrin

Clinical features

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Imported from Human Phenotype Ontology (HPO)

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