Gene
C9
complement C9
- HGNC 1358(opens in a new tab)
- Ensembl gene ENSG00000113600(opens in a new tab)
- NCBI Gene 735(opens in a new tab)
Summary
- Cytogenetic location
- 5p13.1
- Coordinates
- Chromosome 5: 39,284,140–39,364,495 (GRCh38)
- Exons
- 11 exons across 80.4 kb
- Protein
- 559 amino acids
- Inheritance
- Autosomal recessive
- MANE Select transcript
- ENST00000263408.5NM_001737.5
- Locus type
- gene with protein product
- Very high
- Confident
- Low
- Very low
Reference genomeGRCh38hg38
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Inherited Complement and Properdin Deficiencies
- Late complement component deficiency (C5 to C9)Autosomal recessive
Deficiencies of the terminal complement components that greatly increase the risk of recurrent Neisseria infections, especially meningococcal disease.
- 1 GenCC submitter rates it definitive or strong
What knowing changes
Meningococcal vaccination, and in some cases antibiotic prophylaxis, are recommended.
Broader groupings
Other Inborn Errors of Immunity
- Inborn error of immunity
One of 114 genes linked to it
Inherited disorders of the immune system caused by changes in single genes, affecting how the body fights infection or regulates inflammation.
- 1 GenCC submitter rates it definitive or strong
- Immunodeficiency Disease
One of 170 genes linked to it
Disease in which there is a deficiency or defect in the mechanisms of immunity, either cellular or humoral.
- 1 GenCC submitter rates it definitive or strong
What knowing changes
HSCT for SCID and severe PIDs; immunoglobulin replacement (IVIG/SCIG) for antibody deficiencies; leniolisib (Joenja, FDA 2023) for APDS; gene therapy for ADA-SCID; abatacept for CTLA4/LRBA deficiency; prophylactic antibiotics; G-CSF for CGD
Inheritance
- Autosomal recessive
- It takes a changed copy from each parent. With one, you are a carrier and usually unaffected; when both parents are carriers, each child has a one-in-four chance of inheriting two.
How C9 is laid out
- Coding sequence
- Untranslated region
- Intron
- Direction of transcription
- Known disease-causing sites
- Stretches short reads find hard
Exons of the gene's MANE Select transcript (release v1.5), from NCBI and EMBL-EBI, on the GRCh38 reference genome.
Chromosome bands from UCSC's GRCh38 ideogram (2022-10-29).
Nearby genes from Ensembl release 116, on GRCh38.
Exons make up 2.8 kb of the gene's 80.4 kb; 1,680 of those bases code for the protein.
How a genome test reads C9
10
positions in C9 where ClinVar classes a change as pathogenic or likely pathogenic
None of them falls in a region short reads find hard.
A whole genome covers all 80.4 kb of C9, introns included, not only the 2.8 kb of exons.
Traits linked to C9
The Human Phenotype Ontology lists these as features of the rare conditions C9 can cause. Each trait's page lists the other genes linked to it.
External links
Gene records
Transcript
Protein
Where this comes from
- HGNC: the gene's symbol, name, other symbols and location.
- MANE Select v1.5, from NCBI and EMBL-EBI: the transcript, its exons and coding sequence.
- GenCC and ClinGen, released 2026-10-16: which conditions the gene is linked to, and how strongly.
- The ACMG secondary findings list, SF v3.2.
- ClinVar and the GIAB stratifications: known disease-causing sites, and the regions short reads find hard.
- The Human Phenotype Ontology, release 2026-09-01: the traits linked to the gene. Find out more at hpo.jax.org.
- Data release 2026.10.16-c6eea6bf.
Cite this page
Dante Labs. (n.d.). C9 gene: complement C9. Retrieved 16 October 2026, from https://dantelabs.com/genes/c9
Dante Labs. C9 gene: complement C9 [Internet]. [cited 16 October 2026]. Available from: https://dantelabs.com/genes/c9
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