CD9

Chr 12

CD9 molecule

Also known as: BTCC-1, DRAP-27, MIC3, MRP-1, TSPAN-29, TSPAN29

The CD9 protein is a tetraspanin family member that regulates cell adhesion, sperm-egg fusion, platelet activation, and paranodal junction formation by organizing multiprotein complexes at cell surfaces. Mutations cause autosomal recessive oocyte/sperm/zygote-associated proteins deficiency, leading to female infertility. This gene is not highly constrained against loss-of-function variants.

Summary from RefSeq, UniProt
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2
Active trials
327
Pubs (1 yr)
0
P/LP submissions
P/LP missense
0.86
LOEUF
Multiple*
Mechanism· predicted
Clinical SummaryCD9
Population Constraint (gnomAD)
Low constraint (pLI 0.00) — loss-of-function variants are relatively tolerated in the population.
💊
Clinical Trials
2 active or recruiting trials — potential therapeutic options may be available

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.86LOEUF
pLI 0.005
Z-score 1.94
OE 0.44 (0.240.86)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.87Z-score
OE missense 0.79 (0.680.93)
111 obs / 140.1 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.44 (0.240.86)
00.351.4
Missense OE0.79 (0.680.93)
00.61.4
Synonymous OE0.89
01.21.6
LoF obs/exp: 6 / 13.8Missense obs/exp: 111 / 140.1Syn Z: 0.64
DN
0.84top 10%
GOF
0.83top 10%
LOF
0.1299th %ile

This gene has evidence for multiple mechanisms of pathogenicity (dominant-negative and gain-of-function). Both the Badonyi & Marsh prediction and the broader genomic evidence point to dominant-negative as the predominant mechanism. Different variants in this gene may act through different mechanisms — interpret in context of the specific variant.

DNprediction above median
GOFprediction above median

Note: In-silico variant effect predictors (SIFT, PolyPhen, REVEL, CADD) may underestimate pathogenicity of missense variants in genes with GOF or DN mechanisms. Consider functional evidence and clinical context.

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312.

ClinVar Variant Classifications

0 submitted variants in ClinVar

Protein Context — Lollipop Plot

CD9 · protein map & ClinVar variants

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

Clinical Literature
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