CYB5A

Chr 18

cytochrome b5 type A

Also known as: CYB5, MCB5, METAG

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]

ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtMethemoglobinemia and ambiguous genitalia

Clinical highlights

Gene-disease validity (ClinGen)
methemoglobinemia type 4 · ARDefinitivesufficient evidence for diagnostic panels
0
Active trials
15
Pubs (1 yr)
P/LP submissions
P/LP missense
1.43
LOEUF
Multiple*
Mechanism· predicted
Some data sources returned errors (1)

omim: Error: OMIM fetch failed: 429

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint?
1.43LOEUF
pLI 0.002
Z-score 0.78
OE 0.69 (0.361.43)
Tolerant

Highly tolerant — LoF variants common in population

Missense Constraint?
-0.09Z-score
OE missense 1.03 (0.851.24)
76 obs / 73.9 exp
Tolerant

Tolerant to missense variation

Observed / Expected Ratios?
LoF OE?0.69 (0.361.43)
00.351.4
Missense OE?1.03 (0.851.24)
00.61.4
Synonymous OE?1.40
01.21.6
LoF obs/exp: 5 / 7.3Missense obs/exp: 76 / 73.9Syn Z: -1.60

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CYB5A · protein map & ClinVar variants

Showing all ClinVar variants across the protein. Search a specific variant to highlight its position.

Clinical Trials

Active and recruiting trials from ClinicalTrials.gov

No active trials found for this gene.

Search ClinicalTrials.gov →