{
  "url": "https://dantelabs.com/cs/genes/cyb5r3",
  "gene": {
    "slug": "cyb5r3",
    "symbol": "CYB5R3",
    "name": "cytochrome b5 reductase 3",
    "hgnc": "HGNC:2873",
    "summary": null,
    "location": "22q13.2",
    "locusType": "gene with protein product",
    "aliases": [
      "B5R"
    ],
    "previousSymbols": [
      "DIA1"
    ],
    "ensemblId": "ENSG00000100243",
    "entrezId": 1727,
    "omim": [
      "613213"
    ],
    "uniprot": [
      "P00387"
    ],
    "model": {
      "build": "GRCh38",
      "release": "v1.5",
      "chrom": "22",
      "start": 42617840,
      "end": 42649392,
      "strand": "-",
      "ensemblTranscript": "ENST00000352397.10",
      "refseqTranscript": "NM_000398.7",
      "ensemblProtein": "ENSP00000338461.6",
      "refseqProtein": "NP_000389.1",
      "exons": [
        {
          "start": 42617840,
          "end": 42619945
        },
        {
          "start": 42623789,
          "end": 42623888
        },
        {
          "start": 42627304,
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        },
        {
          "start": 42627605,
          "end": 42627688
        },
        {
          "start": 42628152,
          "end": 42628281
        },
        {
          "start": 42630882,
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        },
        {
          "start": 42631378,
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        },
        {
          "start": 42636715,
          "end": 42636846
        },
        {
          "start": 42649295,
          "end": 42649392
        }
      ],
      "cds": {
        "start": 42619773,
        "end": 42649315
      }
    },
    "grch37": {
      "build": "GRCh37",
      "release": "87",
      "chrom": "22",
      "start": 43013846,
      "end": 43045574,
      "strand": "-"
    },
    "neighbourhood": {
      "release": "116",
      "start": 42133616,
      "end": 43133615,
      "genes": [
        {
          "symbol": "CYP2D7",
          "ensemblId": "ENSG00000205702",
          "biotype": "protein_coding",
          "start": 42140203,
          "end": 42149500,
          "strand": "-",
          "slug": "cyp2d7"
        },
        {
          "symbol": "TCF20",
          "ensemblId": "ENSG00000100207",
          "biotype": "protein_coding",
          "start": 42160013,
          "end": 42343616,
          "strand": "-",
          "slug": "tcf20"
        },
        {
          "symbol": "NFAM1",
          "ensemblId": "ENSG00000235568",
          "biotype": "protein_coding",
          "start": 42380407,
          "end": 42432425,
          "strand": "-",
          "slug": "nfam1"
        },
        {
          "symbol": "RRP7A",
          "ensemblId": "ENSG00000189306",
          "biotype": "protein_coding",
          "start": 42507982,
          "end": 42519853,
          "strand": "-",
          "slug": "rrp7a"
        },
        {
          "symbol": "SERHL2",
          "ensemblId": "ENSG00000183569",
          "biotype": "protein_coding",
          "start": 42553617,
          "end": 42574387,
          "strand": "+",
          "slug": "serhl2"
        },
        {
          "symbol": "POLDIP3",
          "ensemblId": "ENSG00000100227",
          "biotype": "protein_coding",
          "start": 42582750,
          "end": 42614962,
          "strand": "-",
          "slug": "poldip3"
        },
        {
          "symbol": "",
          "ensemblId": "ENSG00000289517",
          "biotype": "protein_coding",
          "start": 42583836,
          "end": 42627688,
          "strand": "-"
        },
        {
          "symbol": "RNU12",
          "ensemblId": "ENSG00000276027",
          "biotype": "other",
          "start": 42615244,
          "end": 42615393,
          "strand": "+",
          "slug": "rnu12"
        },
        {
          "symbol": "ATP5MGL",
          "ensemblId": "ENSG00000249222",
          "biotype": "protein_coding",
          "start": 42639803,
          "end": 42640601,
          "strand": "-",
          "slug": "atp5mgl"
        },
        {
          "symbol": "A4GALT",
          "ensemblId": "ENSG00000128274",
          "biotype": "protein_coding",
          "start": 42691010,
          "end": 42721298,
          "strand": "-",
          "slug": "a4galt"
        },
        {
          "symbol": "ARFGAP3",
          "ensemblId": "ENSG00000242247",
          "biotype": "protein_coding",
          "start": 42796502,
          "end": 42858106,
          "strand": "-",
          "slug": "arfgap3"
        },
        {
          "symbol": "PACSIN2",
          "ensemblId": "ENSG00000100266",
          "biotype": "protein_coding",
          "start": 42835412,
          "end": 43015185,
          "strand": "-",
          "slug": "pacsin2"
        },
        {
          "symbol": "TTLL1",
          "ensemblId": "ENSG00000100271",
          "biotype": "protein_coding",
          "start": 43039447,
          "end": 43089430,
          "strand": "-",
          "slug": "ttll1"
        },
        {
          "symbol": "BIK",
          "ensemblId": "ENSG00000100290",
          "biotype": "protein_coding",
          "start": 43110742,
          "end": 43129712,
          "strand": "+",
          "slug": "bik"
        },
        {
          "symbol": "MCAT",
          "ensemblId": "ENSG00000100294",
          "biotype": "protein_coding",
          "start": 43130627,
          "end": 43143401,
          "strand": "-",
          "slug": "mcat"
        }
      ],
      "truncated": false
    },
    "reports": [
      {
        "slug": "hereditary-methaemoglobinaemia-and-unstable-haemoglobins",
        "name": "Hereditary Methaemoglobinaemia and Unstable Haemoglobins",
        "diseases": [
          {
            "mondoId": "MONDO:0018963",
            "name": "Hereditary Methaemoglobinaemia",
            "genes": 4,
            "inheritance": null,
            "description": "Raised methaemoglobin levels from birth, caused by recessive changes in CYB5R3 or CYB5A or by dominant haemoglobin M variants in the globin genes; type II CYB5R3 deficiency also causes severe developmental problems.",
            "management": "Knowing about it explains unexplained cyanosis and helps avoid medicines that raise methaemoglobin, such as dapsone, benzocaine and nitrites; methylene blue treats the enzyme forms but must not be given to people with G6PD deficiency.",
            "evidence": {
              "gencc": [
                "ClinGen",
                "G2P",
                "Labcorp Genetics (formerly Invitae)"
              ],
              "clingen": "Definitive",
              "acmgSf": false,
              "inheritance": [
                "autosomal-recessive"
              ]
            },
            "sameAsReport": false,
            "broad": false
          }
        ],
        "url": "https://dantelabs.com/cs/conditions/hereditary-methaemoglobinaemia-and-unstable-haemoglobins"
      }
    ],
    "pharmacogenomics": [],
    "traits": [],
    "phenotypes": [
      {
        "slug": "abnormal-nail-morphology",
        "name": "Abnormality of the nail",
        "systems": [
          "abnormality-of-the-integument"
        ],
        "frequency": "frequent",
        "url": "https://dantelabs.com/traits/abnormal-nail-morphology"
      },
      {
        "slug": "abnormality-of-the-nervous-system",
        "name": "Abnormality of the nervous system",
        "systems": [],
        "frequency": "frequent",
        "url": "https://dantelabs.com/traits/abnormality-of-the-nervous-system"
      },
      {
        "slug": "microcephaly",
        "name": "Abnormally small head",
        "systems": [
          "abnormality-of-head-or-neck",
          "abnormality-of-the-musculoskeletal-system",
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/microcephaly"
      },
      {
        "slug": "cyanosis",
        "name": "Blue discoloration of the skin",
        "systems": [
          "abnormality-of-the-integument"
        ],
        "frequency": "obligate",
        "url": "https://dantelabs.com/traits/cyanosis"
      },
      {
        "slug": "blue-sclerae",
        "name": "Blue outer white part of eyeball",
        "systems": [
          "abnormality-of-the-eye"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/blue-sclerae"
      },
      {
        "slug": "cerebral-hypomyelination",
        "name": "Cerebral hypomyelination",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/cerebral-hypomyelination"
      },
      {
        "slug": "strabismus",
        "name": "Cross-eyed",
        "systems": [
          "abnormality-of-the-eye"
        ],
        "url": "https://dantelabs.com/traits/strabismus"
      },
      {
        "slug": "decreased-erythrocyte-nicotinamide-adenine-dinucleotide-cytochrome-b5-reductase-activity",
        "name": "Decreased erythrocyte nicotinamide adenine dinucleotide-cytochrome b5 reductase activity",
        "systems": [
          "abnormality-of-blood-and-blood-forming-tissues",
          "abnormality-of-metabolism-homeostasis"
        ],
        "frequency": "obligate",
        "url": "https://dantelabs.com/traits/decreased-erythrocyte-nicotinamide-adenine-dinucleotide-cytochrome-b5-reductase-activity"
      },
      {
        "slug": "cerebellar-atrophy",
        "name": "Degeneration of cerebellum",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/cerebellar-atrophy"
      },
      {
        "slug": "delayed-myelination",
        "name": "Delayed myelination",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "very-rare",
        "url": "https://dantelabs.com/traits/delayed-myelination"
      },
      {
        "slug": "seizure",
        "name": "Epilepsy",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "very-rare",
        "url": "https://dantelabs.com/traits/seizure"
      },
      {
        "slug": "esodeviation",
        "name": "Esodeviation",
        "systems": [
          "abnormality-of-the-eye"
        ],
        "frequency": "obligate",
        "url": "https://dantelabs.com/traits/esodeviation"
      },
      {
        "slug": "exertional-dyspnea",
        "name": "Exertional breathlessness",
        "systems": [
          "abnormality-of-the-respiratory-system"
        ],
        "frequency": "frequent",
        "url": "https://dantelabs.com/traits/exertional-dyspnea"
      },
      {
        "slug": "frontal-cortical-atrophy",
        "name": "Frontal cortical atrophy",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/frontal-cortical-atrophy"
      },
      {
        "slug": "global-brain-atrophy",
        "name": "Generalized brain degeneration",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/global-brain-atrophy"
      },
      {
        "slug": "global-developmental-delay",
        "name": "Global developmental delay",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "obligate",
        "url": "https://dantelabs.com/traits/global-developmental-delay"
      },
      {
        "slug": "growth-delay",
        "name": "Growth delay",
        "systems": [
          "growth-abnormality"
        ],
        "url": "https://dantelabs.com/traits/growth-delay"
      },
      {
        "slug": "headache",
        "name": "Headache",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "url": "https://dantelabs.com/traits/headache"
      },
      {
        "slug": "polycythemia",
        "name": "Increased red blood cells",
        "systems": [
          "abnormality-of-blood-and-blood-forming-tissues"
        ],
        "url": "https://dantelabs.com/traits/polycythemia"
      },
      {
        "slug": "intellectual-disability",
        "name": "Intellectual disability",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "url": "https://dantelabs.com/traits/intellectual-disability"
      },
      {
        "slug": "severe-intellectual-disability",
        "name": "Intellectual disability, severe",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/severe-intellectual-disability"
      },
      {
        "slug": "spasticity",
        "name": "Involuntary muscle stiffness, contraction, or spasm",
        "systems": [
          "abnormality-of-the-musculoskeletal-system",
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/spasticity"
      },
      {
        "slug": "athetosis",
        "name": "Involuntary writhing movements in fingers, hands, toes, and feet",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/athetosis"
      },
      {
        "slug": "esotropia",
        "name": "Inward turning cross eyed",
        "systems": [
          "abnormality-of-the-eye"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/esotropia"
      },
      {
        "slug": "limb-dystonia",
        "name": "Limb dystonia",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/limb-dystonia"
      },
      {
        "slug": "lip-discoloration",
        "name": "Lip discoloration",
        "systems": [
          "abnormality-of-head-or-neck"
        ],
        "frequency": "frequent",
        "url": "https://dantelabs.com/traits/lip-discoloration"
      },
      {
        "slug": "methemoglobinemia",
        "name": "Methemoglobinemia",
        "systems": [
          "abnormality-of-blood-and-blood-forming-tissues"
        ],
        "frequency": "obligate",
        "url": "https://dantelabs.com/traits/methemoglobinemia"
      },
      {
        "slug": "opisthotonus",
        "name": "Opisthotonus",
        "systems": [
          "abnormality-of-the-musculoskeletal-system",
          "abnormality-of-the-nervous-system"
        ],
        "url": "https://dantelabs.com/traits/opisthotonus"
      },
      {
        "slug": "severe-global-developmental-delay",
        "name": "Severe global developmental delay",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/severe-global-developmental-delay"
      },
      {
        "slug": "small-basal-ganglia",
        "name": "Small basal ganglia",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "very-rare",
        "url": "https://dantelabs.com/traits/small-basal-ganglia"
      },
      {
        "slug": "small-for-gestational-age",
        "name": "Small for gestational age",
        "systems": [
          "growth-abnormality"
        ],
        "frequency": "very-rare",
        "url": "https://dantelabs.com/traits/small-for-gestational-age"
      },
      {
        "slug": "spastic-tetraplegia",
        "name": "Spastic tetraplegia",
        "systems": [
          "abnormality-of-the-musculoskeletal-system",
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/spastic-tetraplegia"
      },
      {
        "slug": "hypertonia",
        "name": "Spasticity and rigidity of muscles",
        "systems": [
          "abnormality-of-the-musculoskeletal-system"
        ],
        "frequency": "obligate",
        "url": "https://dantelabs.com/traits/hypertonia"
      },
      {
        "slug": "temporal-cortical-atrophy",
        "name": "Temporal cortical atrophy",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "occasional",
        "url": "https://dantelabs.com/traits/temporal-cortical-atrophy"
      },
      {
        "slug": "tremor",
        "name": "Tremor",
        "systems": [
          "abnormality-of-the-nervous-system"
        ],
        "frequency": "obligate",
        "url": "https://dantelabs.com/traits/tremor"
      }
    ],
    "related": [
      {
        "slug": "cyb5a",
        "symbol": "CYB5A",
        "name": "cytochrome b5 type A",
        "shared": 1,
        "url": "https://dantelabs.com/cs/genes/cyb5a"
      },
      {
        "slug": "hba1",
        "symbol": "HBA1",
        "name": "hemoglobin subunit alpha 1",
        "shared": 1,
        "url": "https://dantelabs.com/cs/genes/hba1"
      },
      {
        "slug": "hbb",
        "symbol": "HBB",
        "name": "hemoglobin subunit beta",
        "shared": 1,
        "url": "https://dantelabs.com/cs/genes/hbb"
      }
    ],
    "sources": {
      "bundleId": "2026.10.17-8666dff2",
      "panel": "2026-10-17",
      "acmgSf": "SF v3.2"
    },
    "locusKind": "proteinCoding"
  },
  "variants": {
    "total": 0,
    "url": null,
    "items": []
  }
}