C1R

Chr 12

complement C1r

Also known as: EDS8, EDSPD1

NCBI Gene: 715 ENSG00000159403 UniProt: P00736

The C1R protein is a serine protease component of the complement C1 complex that catalyzes the first enzymatic step in the classical complement pathway, cleaving and activating C1S to initiate the cascade leading to pathogen destruction and immune signaling. Mutations cause Ehlers-Danlos syndrome, periodontal type, 1, which follows autosomal dominant inheritance. The gene is highly constrained against loss-of-function variants (LOEUF 0.39), indicating intolerance to protein-disrupting mutations.

GeneReviews ResearchSummary from RefSeq, OMIM, UniProt

This gene encodes a member of the peptidase S1 protein family. The encoded protein is a proteolytic subunit in the complement system C1 complex. The complement system acts as a mediator in the innate immune response by ultimately triggering phagocytosis, inflammation, and rupturing the bacterial cell wall. Mutations in this gene are associated with Ehlers-Danlos Syndrome. [provided by RefSeq, Dec 2018]

GeneReviews ResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtEhlers-Danlos syndrome, periodontal type, 1

Clinical highlights

Interpreting a novel variant

This gene is strongly intolerant of loss-of-function variation in the population, so LoF variants warrant close attention. No curated mechanism annotation is available — see the mechanism card for the computational prediction and its caveats.Curated gene-level mechanism — a prior for triage, not a per-variant call.

Active trials

Pubs (1 yr)

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P/LP submissions

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P/LP missense

0.39

LOEUF

GOF

Mechanism· predicted

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GeneReview available — C1R