{
  "url": "https://dantelabs.com/traits/onion-bulb-formation",
  "trait": {
    "bundleId": "2026.10.17-8666dff2",
    "release": "2026-09-01",
    "slug": "onion-bulb-formation",
    "id": "HP:0003383",
    "name": "Onion bulb formation",
    "definition": "Repeated episodes of segmental demyelination and remyelination lead to the accumulation of supernumerary Schwann cells around axons, which is referred to as onion bulb formation. This finding affects peripheral nerves.",
    "synonyms": [],
    "systems": [
      {
        "slug": "abnormality-of-the-nervous-system",
        "name": "Abnormality of the nervous system",
        "url": "https://dantelabs.com/traits/abnormality-of-the-nervous-system"
      }
    ],
    "broader": [
      {
        "slug": "abnormal-peripheral-myelination",
        "name": "Abnormal peripheral myelination",
        "url": "https://dantelabs.com/traits/abnormal-peripheral-myelination"
      }
    ],
    "narrower": [
      {
        "slug": "basal-lamina-onion-bulb-formation",
        "name": "Basal lamina onion bulb formation",
        "genes": 3,
        "url": "https://dantelabs.com/traits/basal-lamina-onion-bulb-formation"
      }
    ],
    "genes": [
      {
        "slug": "afg3l2",
        "symbol": "AFG3L2",
        "hgnc": "HGNC:315",
        "name": "AFG3 like matrix AAA peptidase subunit 2",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/afg3l2"
      },
      {
        "slug": "egr2",
        "symbol": "EGR2",
        "hgnc": "HGNC:3239",
        "name": "early growth response 2",
        "frequency": "obligate",
        "diseases": 2,
        "url": "https://dantelabs.com/genes/egr2"
      },
      {
        "slug": "fgd4",
        "symbol": "FGD4",
        "hgnc": "HGNC:19125",
        "name": "FYVE, RhoGEF and PH domain containing 4",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/fgd4"
      },
      {
        "slug": "gdap1",
        "symbol": "GDAP1",
        "hgnc": "HGNC:15968",
        "name": "ganglioside induced differentiation associated protein 1",
        "frequency": "obligate",
        "diseases": 3,
        "url": "https://dantelabs.com/genes/gdap1"
      },
      {
        "slug": "gjb1",
        "symbol": "GJB1",
        "hgnc": "HGNC:4283",
        "name": "gap junction protein beta 1",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/gjb1"
      },
      {
        "slug": "gnb4",
        "symbol": "GNB4",
        "hgnc": "HGNC:20731",
        "name": "G protein subunit beta 4",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/gnb4"
      },
      {
        "slug": "hycc1",
        "symbol": "HYCC1",
        "hgnc": "HGNC:24587",
        "name": "hyccin PI4KA lipid kinase complex subunit 1",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/hycc1"
      },
      {
        "slug": "inf2",
        "symbol": "INF2",
        "hgnc": "HGNC:23791",
        "name": "inverted formin 2",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/inf2"
      },
      {
        "slug": "mpz",
        "symbol": "MPZ",
        "hgnc": "HGNC:7225",
        "name": "myelin protein zero",
        "frequency": "obligate",
        "diseases": 4,
        "url": "https://dantelabs.com/genes/mpz"
      },
      {
        "slug": "nefl",
        "symbol": "NEFL",
        "hgnc": "HGNC:7739",
        "name": "neurofilament light chain",
        "frequency": "obligate",
        "diseases": 2,
        "url": "https://dantelabs.com/genes/nefl"
      },
      {
        "slug": "pmp2",
        "symbol": "PMP2",
        "hgnc": "HGNC:9117",
        "name": "peripheral myelin protein 2",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/pmp2"
      },
      {
        "slug": "pmp22",
        "symbol": "PMP22",
        "hgnc": "HGNC:9118",
        "name": "peripheral myelin protein 22",
        "frequency": "obligate",
        "diseases": 4,
        "url": "https://dantelabs.com/genes/pmp22"
      },
      {
        "slug": "prx",
        "symbol": "PRX",
        "hgnc": "HGNC:13797",
        "name": "periaxin",
        "frequency": "obligate",
        "diseases": 2,
        "url": "https://dantelabs.com/genes/prx"
      },
      {
        "slug": "sbf1",
        "symbol": "SBF1",
        "hgnc": "HGNC:10542",
        "name": "SET binding factor 1",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/sbf1"
      },
      {
        "slug": "mtrfr",
        "symbol": "MTRFR",
        "hgnc": "HGNC:26784",
        "name": "mitochondrial translation release factor in rescue",
        "frequency": "frequent",
        "diseases": 2,
        "url": "https://dantelabs.com/genes/mtrfr"
      },
      {
        "slug": "arhgef10",
        "symbol": "ARHGEF10",
        "hgnc": "HGNC:14103",
        "name": "Rho guanine nucleotide exchange factor 10",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/arhgef10"
      },
      {
        "slug": "cox6a1",
        "symbol": "COX6A1",
        "hgnc": "HGNC:2277",
        "name": "cytochrome c oxidase subunit 6A1",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/cox6a1"
      },
      {
        "slug": "dcaf8",
        "symbol": "DCAF8",
        "hgnc": "HGNC:24891",
        "name": "DDB1 and CUL4 associated factor 8",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/dcaf8"
      },
      {
        "slug": "dnm2",
        "symbol": "DNM2",
        "hgnc": "HGNC:2974",
        "name": "dynamin 2",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/dnm2"
      },
      {
        "slug": "fig4",
        "symbol": "FIG4",
        "hgnc": "HGNC:16873",
        "name": "FIG4 phosphoinositide 5-phosphatase",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/fig4"
      },
      {
        "slug": "gbf1",
        "symbol": "GBF1",
        "hgnc": "HGNC:4181",
        "name": "golgi brefeldin A resistant guanine nucleotide exchange factor 1",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/gbf1"
      },
      {
        "slug": "kif1b",
        "symbol": "KIF1B",
        "hgnc": "HGNC:16636",
        "name": "kinesin family member 1B",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/kif1b"
      },
      {
        "slug": "litaf",
        "symbol": "LITAF",
        "hgnc": "HGNC:16841",
        "name": "lipopolysaccharide induced TNF factor",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/litaf"
      },
      {
        "slug": "lmna",
        "symbol": "LMNA",
        "hgnc": "HGNC:6636",
        "name": "lamin A/C",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/lmna"
      },
      {
        "slug": "mfn2",
        "symbol": "MFN2",
        "hgnc": "HGNC:16877",
        "name": "mitofusin 2",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/mfn2"
      },
      {
        "slug": "ndrg1",
        "symbol": "NDRG1",
        "hgnc": "HGNC:7679",
        "name": "N-myc downstream regulated 1",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/ndrg1"
      },
      {
        "slug": "prps1",
        "symbol": "PRPS1",
        "hgnc": "HGNC:9462",
        "name": "phosphoribosyl pyrophosphate synthetase 1",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/prps1"
      },
      {
        "slug": "sacs",
        "symbol": "SACS",
        "hgnc": "HGNC:10519",
        "name": "sacsin molecular chaperone",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/sacs"
      },
      {
        "slug": "sbf2",
        "symbol": "SBF2",
        "hgnc": "HGNC:2135",
        "name": "SET binding factor 2",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/sbf2"
      },
      {
        "slug": "slc12a6",
        "symbol": "SLC12A6",
        "hgnc": "HGNC:10914",
        "name": "solute carrier family 12 member 6",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/slc12a6"
      }
    ]
  }
}