{
  "url": "https://dantelabs.com/traits/increased-transitional-b-cell-proportion",
  "trait": {
    "bundleId": "2026.10.16-c6eea6bf",
    "release": "2026-09-01",
    "slug": "increased-transitional-b-cell-proportion",
    "id": "HP:0030381",
    "name": "Increased transitional B cell proportion",
    "definition": "Abnormal increase of the transitional B cell subpopulation, commonly characterized as CD27-CD24hiCD38hi or CD27-IgMhiCD38hi, measured as percentage of total B cells in the blood, compared to a reference range for a given sex and age-group.",
    "synonyms": [
      "Increased proportion of CD19+CD38+IgM+ cells",
      "Increased proportion of transitional B cells"
    ],
    "systems": [
      {
        "slug": "abnormality-of-blood-and-blood-forming-tissues",
        "name": "Abnormality of blood and blood-forming tissues",
        "url": "https://dantelabs.com/traits/abnormality-of-blood-and-blood-forming-tissues"
      },
      {
        "slug": "abnormality-of-the-immune-system",
        "name": "Abnormality of the immune system",
        "url": "https://dantelabs.com/traits/abnormality-of-the-immune-system"
      }
    ],
    "broader": [
      {
        "slug": "abnormal-transitional-b-cell-proportion",
        "name": "Abnormal transitional B cell proportion",
        "url": "https://dantelabs.com/traits/abnormal-transitional-b-cell-proportion"
      }
    ],
    "narrower": [],
    "genes": [
      {
        "slug": "arhgef1",
        "symbol": "ARHGEF1",
        "hgnc": "HGNC:681",
        "name": "Rho guanine nucleotide exchange factor 1",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/arhgef1"
      },
      {
        "slug": "ikzf2",
        "symbol": "IKZF2",
        "hgnc": "HGNC:13177",
        "name": "IKAROS family zinc finger 2",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/ikzf2"
      },
      {
        "slug": "irf4",
        "symbol": "IRF4",
        "hgnc": "HGNC:6119",
        "name": "interferon regulatory factor 4",
        "frequency": "obligate",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/irf4"
      },
      {
        "slug": "pik3cd",
        "symbol": "PIK3CD",
        "hgnc": "HGNC:8977",
        "name": "phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit delta",
        "frequency": "very-frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/pik3cd"
      },
      {
        "slug": "irf1",
        "symbol": "IRF1",
        "hgnc": "HGNC:6116",
        "name": "interferon regulatory factor 1",
        "frequency": "frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/irf1"
      },
      {
        "slug": "pik3r1",
        "symbol": "PIK3R1",
        "hgnc": "HGNC:8979",
        "name": "phosphoinositide-3-kinase regulatory subunit 1",
        "frequency": "frequent",
        "diseases": 1,
        "url": "https://dantelabs.com/genes/pik3r1"
      }
    ]
  }
}