{
  "url": "https://dantelabs.com/traits/absent-bell-phenomenon",
  "trait": {
    "bundleId": "2026.10.19-9814e911",
    "release": "2026-09-01",
    "slug": "absent-bell-phenomenon",
    "id": "HP:6000709",
    "name": "Absent Bell phenomenon",
    "definition": "The Bell phenomenon is the reflex upward movement of the front of the eyeball when the eyelids close (or blink). It protects the eye by helping to keep the cornea moist. This term refers to a lack of this phenomenon, which can be observed with certain conditions such as congenital fibrosis of the extraocular muscles.",
    "synonyms": [
      "Absent palpebral-oculogyric reflex"
    ],
    "systems": [
      {
        "slug": "abnormality-of-the-eye",
        "name": "Abnormality of the eye",
        "url": "https://dantelabs.com/traits/abnormality-of-the-eye"
      }
    ],
    "broader": [
      {
        "slug": "abnormal-involuntary-eye-movements",
        "name": "Abnormal involuntary eye movements",
        "url": "https://dantelabs.com/traits/abnormal-involuntary-eye-movements"
      }
    ],
    "narrower": [],
    "genes": [
      {
        "slug": "col25a1",
        "symbol": "COL25A1",
        "hgnc": "HGNC:18603",
        "name": "collagen type XXV alpha 1 chain",
        "frequency": "very-frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/col25a1"
      },
      {
        "slug": "kif21a",
        "symbol": "KIF21A",
        "hgnc": "HGNC:19349",
        "name": "kinesin family member 21A",
        "frequency": "very-frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/kif21a"
      },
      {
        "slug": "phox2a",
        "symbol": "PHOX2A",
        "hgnc": "HGNC:691",
        "name": "paired like homeobox 2A",
        "frequency": "very-frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/phox2a"
      },
      {
        "slug": "tuba1a",
        "symbol": "TUBA1A",
        "hgnc": "HGNC:20766",
        "name": "tubulin alpha 1a",
        "frequency": "very-frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/tuba1a"
      },
      {
        "slug": "tubb2b",
        "symbol": "TUBB2B",
        "hgnc": "HGNC:30829",
        "name": "tubulin beta 2B class IIb",
        "frequency": "very-frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/tubb2b"
      },
      {
        "slug": "tubb3",
        "symbol": "TUBB3",
        "hgnc": "HGNC:20772",
        "name": "tubulin beta 3 class III",
        "frequency": "very-frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/tubb3"
      }
    ]
  }
}