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IEMbase 0522: SLC6A5-related glycine transporter 2 deficiency

Scope

Field Value
IEMbase ID 522
Nosology 17.4.02.03
Gene SLC6A5
External IDs OMIM:149400; ORPHA:3197
Generated mapping MAPPED; Hereditary_Hyperekplexia.yaml
Candidate DisMech targets Hereditary_Hyperekplexia.yaml
Review date 2026-07-07

IEMbase phenotype signal

IEMbase represents this as SLC6A5-related glycine transporter 2 deficiency, with alternate labels hereditary hyperekplexia type 3, familial startle disease, stiff-baby syndrome, and HE. No biochemical rows or treatment rows are listed.

Clinical-characteristic rows include increased head-retraction reflex, startle reflex, and stiffness. Additional clinical rows include optional hernias, hip dislocation, intellectual disability, periodic limb movement during sleep, and sudden infant death.

DisMech phenotype coverage

Hereditary_Hyperekplexia.yaml is the correct target. The local entry models inhibitory glycinergic neurotransmission failure and explicitly includes SLC6A5 as the presynaptic glycine transporter GlyT2 branch. It covers SLC6A5 variants, defective GlyT2 localization or glycine uptake, exaggerated startle, hypertonia or stiffness, neonatal apnea, developmental delay/intellectual disability context, and the broader GLRA1/GLRB/GPHN/ATAD1 hyperekplexia spectrum.

Concordance and completeness

Judgement: correct mapping with high concordance.

IEMbase and DisMech agree on SLC6A5/GlyT2 identity and the core startle/stiffness phenotype. DisMech is richer for glycinergic synapse pathophysiology and broader gene-spectrum context. IEMbase adds practical phenotype prompts for head-retraction reflex, hernias, hip dislocation, periodic limb movement during sleep, and sudden infant death.

Curation actions

  • Keep this record mapped to Hereditary_Hyperekplexia.yaml.
  • Consider whether head-retraction reflex, periodic limb movements, hernias, hip dislocation, and sudden infant death should be reviewed as future enrichment prompts for the hyperekplexia entry.
  • Preserve the SLC6A5/GlyT2 subtype language when importing aliases.