{
  "url": "https://dantelabs.com/traits/neck-hypertonia",
  "trait": {
    "bundleId": "2026.10.17-8666dff2",
    "release": "2026-09-01",
    "slug": "neck-hypertonia",
    "id": "HP:0031867",
    "name": "Neck hypertonia",
    "definition": "Increased passive stiffness or tightness of the neck musculature.",
    "synonyms": [],
    "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": "hypertonia",
        "name": "Spasticity and rigidity of muscles",
        "url": "https://dantelabs.com/traits/hypertonia"
      }
    ],
    "narrower": [],
    "genes": [
      {
        "slug": "aass",
        "symbol": "AASS",
        "hgnc": "HGNC:17366",
        "name": "aminoadipate-semialdehyde synthase",
        "frequency": "occasional",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/aass"
      }
    ]
  }
}