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Aliases for CYB5A Gene

Aliases for CYB5A Gene

  • Cytochrome B5 Type A 2 3 5
  • Cytochrome B5 Type A (Microsomal) 2 3
  • CYB5 3 4
  • MCB5 3 4
  • Microsomal Cytochrome B5 Type A 4
  • Cytochrome B5 (Microsomal) 2
  • Cytochrome B-5 2
  • Cytochrome B5 3
  • Type 1 Cyt-B5 3
  • METAG 3

External Ids for CYB5A Gene

Previous HGNC Symbols for CYB5A Gene

  • CYB5

Previous GeneCards Identifiers for CYB5A Gene

  • GC18M070072
  • GC18M071920
  • GC18M068652

Summaries for CYB5A Gene

Entrez Gene Summary for CYB5A Gene

  • The protein encoded by this gene is a membrane-bound cytochrome that reduces ferric hemoglobin (methemoglobin) to ferrous hemoglobin, which is required for stearyl-CoA-desaturase activity. Defects in this gene are a cause of type IV hereditary methemoglobinemia. Three transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2010]

GeneCards Summary for CYB5A Gene

CYB5A (Cytochrome B5 Type A) is a Protein Coding gene. Diseases associated with CYB5A include Methemoglobinemia And Ambiguous Genitalia and Adrenal Hyperplasia, Congenital, Due To 17-Alpha-Hydroxylase Deficiency. Among its related pathways are Metabolism and Methylene Blue Pathway, Pharmacodynamics. Gene Ontology (GO) annotations related to this gene include enzyme binding and cytochrome-c oxidase activity. An important paralog of this gene is CYB5B.

UniProtKB/Swiss-Prot for CYB5A Gene

  • Cytochrome b5 is a membrane bound hemoprotein which function as an electron carrier for several membrane bound oxygenases.

Gene Wiki entry for CYB5A Gene

Additional gene information for CYB5A Gene

No data available for CIViC summary , Tocris Summary , PharmGKB "VIP" Summary , fRNAdb sequence ontologies and piRNA Summary for CYB5A Gene

Genomics for CYB5A Gene

GeneHancer (GH) Regulatory Elements for CYB5A Gene

Promoters and enhancers for CYB5A Gene
GeneHancer (GH) Identifier GH Type GH
GH Sources Gene Association Score Total Score TSS distance (kb) Number of Genes Away Size (kb) Transcription Factor
Binding Sites
Gene Targets
GH18J074288 Promoter/Enhancer 2.4 EPDnew Ensembl ENCODE dbSUPER 665.7 +1.4 1407 4.9 HDGF FOXA2 PKNOX1 MLX ARID4B SIN3A DMAP1 YY1 SLC30A9 ZNF207 CYB5A ZNF407 C18orf63 GC18M074254 GC18M074253
GH18J074248 Enhancer 1.6 FANTOM5 Ensembl ENCODE dbSUPER 21.1 +41.7 41694 4.6 PKNOX1 FOXA2 MLX ARID4B SIN3A ZNF48 ETS1 YY1 SLC30A9 FOS CYB5A C18orf63 CNDP2 GC18M074254 GC18M074253 ENSG00000260569
GH18J074242 Enhancer 1.3 FANTOM5 ENCODE dbSUPER 24.5 +49.3 49250 1.5 PKNOX1 ATF1 ARNT DMAP1 YY1 TCF12 ZNF766 GATA2 ATF7 RXRA CYB5A ENSG00000260569 GC18M074254 GC18M074253
GH18J074232 Enhancer 1.3 Ensembl ENCODE dbSUPER 17.9 +57.4 57400 4.2 FOXA2 MLX ARID4B SIN3A FEZF1 DMAP1 ETS1 YY1 SLC30A9 NFKBIZ CYB5A C18orf63 RN7SL551P ENSG00000260569
GH18J074146 Promoter/Enhancer 2.1 EPDnew Ensembl ENCODE 10.8 +143.9 143938 3.8 PKNOX1 MLX ARNT ARID4B SIN3A DMAP1 ZNF2 IRF4 YY1 POLR2B TIMM21 FBXO15 ZNF407 CYB5A
- Elite GeneHancer and/or Elite GeneHancer-gene association Download GeneHancer data from 2017 publication | Request up-to-date GeneHancer data (full dataset)

GeneHancers around CYB5A on UCSC Golden Path with GeneCards custom track

Top Transcription factor binding sites by QIAGEN in the CYB5A gene promoter:
  • NF-YB
  • NF-YA
  • NF-Y
  • CP1A
  • CBF-B
  • CBF-A
  • CBF(2)
  • CUTL1
  • Bach2
  • STAT1

Genomic Locations for CYB5A Gene

Genomic Locations for CYB5A Gene
41,170 bases
Minus strand
38,725 bases
Minus strand

Genomic View for CYB5A Gene

Genes around CYB5A on UCSC Golden Path with GeneCards custom track

Cytogenetic band:
CYB5A Gene in genomic location: bands according to Ensembl, locations according to GeneLoc (and/or Entrez Gene and/or Ensembl if different)
Genomic Location for CYB5A Gene
GeneLoc Logo Genomic Neighborhood Exon StructureGene Density

RefSeq DNA sequence for CYB5A Gene

Proteins for CYB5A Gene

  • Protein details for CYB5A Gene (UniProtKB/Swiss-Prot)

    Protein Symbol:
    Recommended name:
    Cytochrome b5
    Protein Accession:
    Secondary Accessions:
    • A8MV91
    • F8WEU4
    • Q6IB14

    Protein attributes for CYB5A Gene

    134 amino acids
    Molecular mass:
    15330 Da
    Quaternary structure:
    No Data Available
    • Sequence=AAA63169.1; Type=Erroneous gene model prediction; Evidence={ECO:0000305};

    Three dimensional structures from OCA and Proteopedia for CYB5A Gene

    Alternative splice isoforms for CYB5A Gene


neXtProt entry for CYB5A Gene

Post-translational modifications for CYB5A Gene

  • Ubiquitination at Lys39 and posLast=1010
  • Modification sites at PhosphoSitePlus

Other Protein References for CYB5A Gene

No data available for DME Specific Peptides for CYB5A Gene

Domains & Families for CYB5A Gene

Gene Families for CYB5A Gene

Human Protein Atlas (HPA):
  • Disease related genes
  • Plasma proteins
  • Predicted intracellular proteins
  • Predicted membrane proteins

Protein Domains for CYB5A Gene

Suggested Antigen Peptide Sequences for CYB5A Gene

Graphical View of Domain Structure for InterPro Entry



  • Belongs to the cytochrome b5 family.
  • Belongs to the cytochrome b5 family.
genes like me logo Genes that share domains with CYB5A: view

Function for CYB5A Gene

Molecular function for CYB5A Gene

UniProtKB/Swiss-Prot Function:
Cytochrome b5 is a membrane bound hemoprotein which function as an electron carrier for several membrane bound oxygenases.

Gene Ontology (GO) - Molecular Function for CYB5A Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0004033 aldo-keto reductase (NADP) activity TAS --
GO:0004129 cytochrome-c oxidase activity TAS 1712589
GO:0019899 enzyme binding IPI 15680923
GO:0020037 heme binding IEA --
GO:0046872 metal ion binding IEA --
genes like me logo Genes that share ontologies with CYB5A: view
genes like me logo Genes that share phenotypes with CYB5A: view

Human Phenotype Ontology for CYB5A Gene

HPO Id HPO Name Alternative Ids Definition Synonyms

Animal Model Products

CRISPR Products

Inhibitory RNA Products

  • Search GeneCopoeia for shRNA, lentivirus and/or AAV clone products for CYB5A

Clone Products

No data available for Enzyme Numbers (IUBMB) , Phenotypes From GWAS Catalog , Animal Models , Transcription Factor Targets and HOMER Transcription for CYB5A Gene

Localization for CYB5A Gene

Subcellular locations from UniProtKB/Swiss-Prot for CYB5A Gene

Isoform 1: Endoplasmic reticulum membrane; Single-pass membrane protein; Cytoplasmic side. Microsome membrane; Single-pass membrane protein; Cytoplasmic side.
Isoform 2: Cytoplasm.

Subcellular locations from

Extracellular space Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi Apparatus Nucleus Mitochondrion 0 1 2 3 4 5 Confidence
COMPARTMENTS Subcellular localization image for CYB5A gene
Compartment Confidence
extracellular 5
mitochondrion 5
endoplasmic reticulum 5
cytosol 5
nucleus 3
plasma membrane 2
peroxisome 1
lysosome 1
golgi apparatus 1

Subcellular locations from the

Human Protein Atlas (HPA)
  • Cytosol (2)
  • Vesicles (2)
See all subcellular structures

Gene Ontology (GO) - Cellular Components for CYB5A Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0005737 cytoplasm IEA --
GO:0005739 mitochondrion IEA --
GO:0005741 mitochondrial outer membrane TAS --
GO:0005783 endoplasmic reticulum IEA --
GO:0005789 endoplasmic reticulum membrane IEA --
genes like me logo Genes that share ontologies with CYB5A: view

Pathways & Interactions for CYB5A Gene

genes like me logo Genes that share pathways with CYB5A: view

Pathways by source for CYB5A Gene

Gene Ontology (GO) - Biological Process for CYB5A Gene

GO ID Qualified GO term Evidence PubMed IDs
GO:0019852 L-ascorbic acid metabolic process TAS --
GO:0022900 electron transport chain IEA --
GO:0046686 response to cadmium ion IEA --
GO:0055114 oxidation-reduction process IEA --
GO:1902600 proton transmembrane transport IEA --
genes like me logo Genes that share ontologies with CYB5A: view

No data available for SIGNOR curated interactions for CYB5A Gene

Drugs & Compounds for CYB5A Gene

(50) Drugs for CYB5A Gene - From: DrugBank, HMDB, and Novoseek

Name Status Disease Links Group Role Mechanism of Action Clinical Trials
Chromium Approved Pharma Target, substrate 143
Dimethyl Propionate Ester Heme Experimental Pharma Target 0
heme Pharma Agonist 0

(54) Additional Compounds for CYB5A Gene - From: Novoseek

Name Synonyms Role CAS Number PubChem IDs PubMed IDs
genes like me logo Genes that share compounds with CYB5A: view

Transcripts for CYB5A Gene

mRNA/cDNA for CYB5A Gene

Unigene Clusters for CYB5A Gene

Cytochrome b5 type A (microsomal):
Representative Sequences:

CRISPR Products

Inhibitory RNA Products

  • Search GeneCopoeia for shRNA, lentivirus and/or AAV clone products for CYB5A

Clone Products

Alternative Splicing Database (ASD) splice patterns (SP) for CYB5A Gene

No ASD Table

Relevant External Links for CYB5A Gene

GeneLoc Exon Structure for
ECgene alternative splicing isoforms for

Expression for CYB5A Gene

mRNA expression in normal human tissues from GTEx, Illumina, BioGPS, and CGAP SAGE for CYB5A Gene

mRNA expression in embryonic tissues and stem cells from LifeMap Discovery

mRNA differential expression in normal tissues according to GTEx for CYB5A Gene

This gene is overexpressed in Liver (x12.3) and Kidney - Cortex (x5.1).

Protein differential expression in normal tissues from HIPED for CYB5A Gene

This gene is overexpressed in Liver, secretome (11.8), Adipocyte (10.9), and Liver (9.9).

Integrated Proteomics: protein expression in normal tissues and cell lines from ProteomicsDB, MaxQB, and MOPED for CYB5A Gene

Protein tissue co-expression partners for CYB5A Gene

- Elite partner

NURSA nuclear receptor signaling pathways regulating expression of CYB5A Gene:


SOURCE GeneReport for Unigene cluster for CYB5A Gene:


Evidence on tissue expression from TISSUES for CYB5A Gene

  • Liver(4.9)
  • Blood(4.4)
  • Pancreas(4.4)
  • Kidney(3.3)
  • Lung(3.1)
  • Adrenal gland(3)
  • Skin(2.5)
  • Nervous system(2.5)
  • Stomach(2.4)
  • Gall bladder(2.3)
  • Heart(2)
  • Intestine(2)

Phenotype-based relationships between genes and organs from Gene ORGANizer for CYB5A Gene

Germ Layers:
  • ectoderm
  • endoderm
  • mesoderm
  • cardiovascular
  • endocrine
  • integumentary
  • nervous
  • reproductive
  • skeletal muscle
  • urinary
Head and neck:
  • ear
  • pituitary gland
  • breast
  • heart
  • adrenal gland
  • kidney
  • pancreas
  • ovary
  • penis
  • testicle
  • uterus
  • vagina
  • vulva
  • blood
  • blood vessel
  • peripheral nerve
  • peripheral nervous system
  • red blood cell
  • skin
genes like me logo Genes that share expression patterns with CYB5A: view

No data available for mRNA Expression by UniProt/SwissProt for CYB5A Gene

Orthologs for CYB5A Gene

This gene was present in the common ancestor of eukaryotes.

Orthologs for CYB5A Gene

Organism Taxonomy Gene Similarity Type Details
(Pan troglodytes)
Mammalia LOC735913 33
  • 99.25 (n)
CYB5A 34
  • 99 (a)
(Canis familiaris)
Mammalia CYB5A 34 33
  • 88.06 (n)
(Rattus norvegicus)
Mammalia Cyb5a 33
  • 87.06 (n)
(Mus musculus)
Mammalia Cyb5 34 33
  • 86.32 (n)
Cyb5a 16
(Bos Taurus)
Mammalia CYB5A 34 33
  • 84.58 (n)
(Monodelphis domestica)
Mammalia CYB5A 34
  • 84 (a)
(Ornithorhynchus anatinus)
Mammalia CYB5A 34
  • 66 (a)
(Gallus gallus)
Aves CYB5A 34 33
  • 76.61 (n)
(Anolis carolinensis)
Reptilia CYB5A 34
  • 68 (a)
tropical clawed frog
(Silurana tropicalis)
Amphibia cyb5a 33
  • 73.48 (n)
(Danio rerio)
Actinopterygii cyb5a 34 33
  • 65.35 (n)
African malaria mosquito
(Anopheles gambiae)
Insecta AgaP_AGAP007121 33
  • 56.64 (n)
fruit fly
(Drosophila melanogaster)
Insecta Cyt-b5 34 33
  • 54.69 (n)
CG3566 34
  • 38 (a)
CG5157 34
  • 31 (a)
CG6870 34
  • 26 (a)
(Caenorhabditis elegans)
Secernentea cytb-5.1 34 33
  • 53.49 (n)
cytb-5.2 34
  • 34 (a)
baker's yeast
(Saccharomyces cerevisiae)
Saccharomycetes CYB5 34
  • 30 (a)
thale cress
(Arabidopsis thaliana)
eudicotyledons CB5-E 33
  • 54.02 (n)
(Oryza sativa)
Liliopsida Os10g0518200 33
  • 58.44 (n)
sea squirt
(Ciona savignyi)
Ascidiacea CSA.7428 34
  • 60 (a)
Species where no ortholog for CYB5A was found in the sources mined by GeneCards:
  • A. gosspyii yeast (Ashbya gossypii)
  • Actinobacteria (Mycobacterium tuberculosis)
  • African clawed frog (Xenopus laevis)
  • Alicante grape (Vitis vinifera)
  • alpha proteobacteria (Wolbachia pipientis)
  • amoeba (Dictyostelium discoideum)
  • Archea (Pyrococcus horikoshii)
  • barley (Hordeum vulgare)
  • beta proteobacteria (Neisseria meningitidis)
  • bread mold (Neurospora crassa)
  • Chromalveolata (Phytophthora infestans)
  • common water flea (Daphnia pulex)
  • corn (Zea mays)
  • E. coli (Escherichia coli)
  • filamentous fungi (Aspergillus nidulans)
  • Firmicute bacteria (Streptococcus pneumoniae)
  • fission yeast (Schizosaccharomyces pombe)
  • green algae (Chlamydomonas reinhardtii)
  • honey bee (Apis mellifera)
  • K. lactis yeast (Kluyveromyces lactis)
  • loblloly pine (Pinus taeda)
  • malaria parasite (Plasmodium falciparum)
  • medicago trunc (Medicago Truncatula)
  • moss (Physcomitrella patens)
  • orangutan (Pongo pygmaeus)
  • pig (Sus scrofa)
  • rainbow trout (Oncorhynchus mykiss)
  • rice blast fungus (Magnaporthe grisea)
  • schistosome parasite (Schistosoma mansoni)
  • sea anemone (Nematostella vectensis)
  • sea urchin (Strongylocentrotus purpuratus)
  • sorghum (Sorghum bicolor)
  • soybean (Glycine max)
  • stem rust fungus (Puccinia graminis)
  • sugarcane (Saccharum officinarum)
  • tomato (Lycopersicon esculentum)
  • toxoplasmosis (Toxoplasma gondii)
  • Trichoplax (Trichoplax adhaerens)
  • wheat (Triticum aestivum)

Evolution for CYB5A Gene

Gene Tree for CYB5A (if available)
Gene Tree for CYB5A (if available)
Evolutionary constrained regions (ECRs) for CYB5A: view image

Paralogs for CYB5A Gene

Paralogs for CYB5A Gene

(7) SIMAP similar genes for CYB5A Gene using alignment to 2 proteins:

  • J3KNC7_HUMAN Pseudogenes for CYB5A Gene

genes like me logo Genes that share paralogs with CYB5A: view

Variants for CYB5A Gene

Sequence variations from dbSNP and Humsavar for CYB5A Gene

SNP ID Clin Chr 18 pos Variation AA Info Type
rs794728010 pathogenic, Methemoglobinemia type 4 74,263,479(-) T/C splice_acceptor_variant
rs75160992 uncertain-significance, not specified 74,291,863(-) A/C coding_sequence_variant, missense_variant
rs1000025365 -- 74,265,303(-) C/T intron_variant
rs1000036873 -- 74,264,962(-) A/G intron_variant
rs1000111714 -- 74,260,629(-) G/A intron_variant

Structural Variations from Database of Genomic Variants (DGV) for CYB5A Gene

Variant ID Type Subtype PubMed ID
esv2717341 CNV deletion 23290073
esv3643111 CNV loss 21293372
esv3643112 CNV loss 21293372
nsv2356 CNV insertion 18451855
nsv519101 CNV loss 19592680

Variation tolerance for CYB5A Gene

Residual Variation Intolerance Score: 51.2% of all genes are more intolerant (likely to be disease-causing)
Gene Damage Index Score: 1.15; 23.20% of all genes are more intolerant (likely to be disease-causing)

Additional Variant Information for CYB5A Gene

Human Gene Mutation Database (HGMD)
SNPedia medical, phenotypic, and genealogical associations of SNPs for

SNP Genotyping and Copy Number Assay Products

No data available for Polymorphic Variants from UniProtKB/Swiss-Prot for CYB5A Gene

Disorders for CYB5A Gene

MalaCards: The human disease database

(7) MalaCards diseases for CYB5A Gene - From: HGMD, OMIM, ClinVar, GTR, Orphanet, DISEASES, Novoseek, and GeneCards

- elite association - COSMIC cancer census association via MalaCards
Search CYB5A in MalaCards View complete list of genes associated with diseases


  • Methemoglobinemia CYB5A-related (METHB-CYB5A) [MIM:250790]: A form of methemoglobinemia, a hematologic disease characterized by the presence of excessive amounts of methemoglobin in blood cells, resulting in decreased oxygen carrying capacity of the blood, cyanosis and hypoxia. {ECO:0000269 PubMed:8168836}. Note=The disease is caused by mutations affecting the gene represented in this entry.

Additional Disease Information for CYB5A

genes like me logo Genes that share disorders with CYB5A: view

No data available for Genatlas for CYB5A Gene

Publications for CYB5A Gene

  1. Isolated 17,20-lyase deficiency due to the cytochrome b5 mutation W27X. (PMID: 20080843) Kok RC … de Jong FH (The Journal of clinical endocrinology and metabolism 2010) 3 22 58
  2. Cytochrome b5 and NADH cytochrome b5 reductase: genotype-phenotype correlations for hydroxylamine reduction. (PMID: 19997042) Sacco JC … Trepanier LA (Pharmacogenetics and genomics 2010) 3 22 58
  3. Cytochrome b5, not superoxide anion radical, is a major reductant of indoleamine 2,3-dioxygenase in human cells. (PMID: 18299324) Maghzal GJ … Stocker R (The Journal of biological chemistry 2008) 3 22 58
  4. Reduction of hexavalent chromium by human cytochrome b5: generation of hydroxyl radical and superoxide. (PMID: 17320757) Borthiry GR … Myers CR (Free radical biology & medicine 2007) 3 22 58
  5. Regulation of cytochrome b5 gene transcription by Sp3, GATA-6, and steroidogenic factor 1 in human adrenal NCI-H295A cells. (PMID: 15831526) Huang N … Miller WL (Molecular endocrinology (Baltimore, Md.) 2005) 3 22 58

Products for CYB5A Gene

Sources for CYB5A Gene

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