COL9A1

Chr 6

collagen type IX alpha 1 chain

Also known as: DJ149L1.1.2, EDM6, MED, STL4

This gene encodes one of the three alpha chains of type IX collagen, which is a minor (5-20%) collagen component of hyaline cartilage. Type IX collagen is usually found in tissues containing type II collagen, a fibrillar collagen. Studies in knockout mice have shown that synthesis of the alpha 1 chain is essential for assembly of type IX collagen molecules, a heterotrimeric molecule, and that lack of type IX collagen is associated with early onset osteoarthritis. Mutations in this gene are associated with osteoarthritis in humans, with multiple epiphyseal dysplasia, 6, a form of chondrodysplasia, and with Stickler syndrome, a disease characterized by ophthalmic, orofacial, articular, and auditory defects. Two transcript variants that encode different isoforms have been identified for this gene. [provided by RefSeq, Jul 2008]

GeneReviewsResearchGenerating clinical summary…

Primary Disease Associations & Inheritance

UniProtMultiple epiphyseal dysplasia 6
UniProtStickler syndrome 4

Clinical highlights

Gene-disease validity (ClinGen)
Stickler syndrome, type 4 · ARDefinitivesufficient evidence for diagnostic panels
Interpreting a novel variant
Loss of function is the curated mechanism (Gene2Phenotype), though the gene is not strongly LoF-constrained in the population — weigh truncating variants against that tolerance.Curated gene-level mechanism — a prior for triage, not a per-variant call.
0
Active trials
35
Pubs (1 yr)
P/LP submissions
P/LP missense
0.81
LOEUF
Multiple*
Mechanism· G2P
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GeneReview available — COL9A1
Authoritative clinical overview · Recommended first read
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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?
0.81LOEUF
pLI 0.000
Z-score 2.78
OE 0.63 (0.480.81)
Tolerant

Typical tolerance to LoF variation

Missense Constraint?
0.19Z-score
OE missense 0.98 (0.911.05)
514 obs / 526.0 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios?
LoF OE?0.63 (0.480.81)
00.351.4
Missense OE?0.98 (0.911.05)
00.61.4
Synonymous OE?1.25
01.21.6
LoF obs/exp: 40 / 64.0Missense obs/exp: 514 / 526.0Syn Z: -2.58

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

COL9A1 · 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.

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