{
  "url": "https://dantelabs.com/traits/craniocervical-junction-constriction",
  "trait": {
    "bundleId": "2026.10.17-8666dff2",
    "release": "2026-09-01",
    "slug": "craniocervical-junction-constriction",
    "id": "HP:6000920",
    "name": "Craniocervical junction constriction",
    "definition": "Congenital or acquired abnormalities of the occipital bone, foramen magnum, or first two cervical vertebrae that decrease the space for the lower brain stem and cervical cord. These malformations can lead to cranial nerve compression, vertebral artery compression, and obstructive hydrocephalus.",
    "synonyms": [
      "Tight craniocervical junction",
      "Tight craniovertebral junction"
    ],
    "systems": [
      {
        "slug": "abnormality-of-the-musculoskeletal-system",
        "name": "Abnormality of the musculoskeletal system",
        "url": "https://dantelabs.com/traits/abnormality-of-the-musculoskeletal-system"
      }
    ],
    "broader": [
      {
        "slug": "abnormal-cervical-spine-morphology",
        "name": "Abnormal cervical spine morphology",
        "url": "https://dantelabs.com/traits/abnormal-cervical-spine-morphology"
      }
    ],
    "narrower": [],
    "genes": [
      {
        "slug": "fgfr3",
        "symbol": "FGFR3",
        "hgnc": "HGNC:3690",
        "name": "fibroblast growth factor receptor 3",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/fgfr3"
      }
    ]
  }
}