TBX2

Chr 17AD

T-box transcription factor 2

Also known as: VETD

NCBI Gene: 6909 ENSG00000121068 UniProt: Q13207

This gene is a member of a phylogenetically conserved family of genes that share a common DNA-binding domain, the T-box. T-box genes encode transcription factors involved in the regulation of developmental processes. This gene product is the human homolog of mouse Tbx2, and shares strong sequence similarity with Drosophila omb protein. Expression studies indicate that this gene may have a potential role in tumorigenesis as an immortalizing agent. Transcript heterogeneity due to alternative polyadenylation has been noted for this gene. [provided by RefSeq, Jul 2008]

Primary Disease Associations & Inheritance

Vertebral anomalies and variable endocrine and T-cell dysfunctionMIM #618223

Active trials

Pathogenic / LP

193

ClinVar variants

Pubs (1 yr)

1.5

Missense Z

0.25

LOEUF· LoF intolerant

Clinical Summary— TBX2

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Population Constraint (gnomAD)

Highly constrained gene — heterozygous loss-of-function variants are very rare in the population (pLI 0.99). One damaged copy is likely sufficient to cause disease.

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ClinVar Variants

25 Pathogenic / Likely Pathogenic· 121 VUS of 193 total submissions

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GeneReview available — TBX2

Authoritative clinical overview · Recommended first read

Open GeneReview ↗

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

gnomAD

LoF intolerant — likely haploinsufficient

LoF Constraint?LOEUF (Loss-of-function Observed/Expected Upper bound Fraction) is the upper bound of the 90% CI for LoF OE — the preferred gnomAD v4 metric. Lower = more intolerant to LoF. LOEUF < 0.35 = highly constrained.

0.25LOEUF

pLI 0.993

Z-score 3.86

OE 0.05 (0.02–0.25)

Highly constrained

Highly LoF-intolerant (top ~10% of genes)

Missense Constraint?Missense Z-score: standard deviations fewer missense variants observed vs. expected. Z > 3.09 (p < 0.001) = gene does not tolerate missense variation. OE missense < 0.6 is also considered constrained.

1.54Z-score

OE missense 0.78 (0.70–0.85)

288 obs / 371.4 exp

Tolerant

Mild missense constraint

Observed / Expected Ratios?Shaded band = 90% confidence interval. Vertical tick = point estimate. Grey threshold line = gnomAD constraint cutoff for that variant class.

LoF OE?Ratio of observed to expected LoF variants. Upper CI bound (LOEUF) ≤ 0.35 = strong LoF constraint signal.0.05 (0.02–0.25)

0≤0.351.4

Missense OE?Ratio of observed to expected missense variants. OE ≤ 0.6 = fewer missense variants than expected by chance.0.78 (0.70–0.85)

0≤0.61.4

Synonymous OE?Control metric — synonymous variants are largely neutral and expected near OE = 1.0. Significant deviation may indicate annotation issues.0.89

0≤1.21.6

LoF obs/exp: 1 / 19.3Missense obs/exp: 288 / 371.4Syn Z: 1.11

0.4189th %ile

GOF

0.3094th %ile

LOF

0.82top 5%

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

LOFprediction above median · 1 literature citation · LOEUF 0.25

DN1 literature citation

Literature Evidence

DNIn this study we show that TBX2 drives proliferation in breast cancer cells and this is abrogated after TBX2 small interfering RNA (siRNA) knockdown or after the expression of a dominant-negative TBX2 protein.PMID:20348948

LOFThese findings reveal an indispensable T-box gene network governing pharyngeal and OFT development and identify TBX2 and TBX3 as potential modifier genes of the cardiopharyngeal phenotypes found in TBX1-haploinsufficient 22q11.2DS patients.PMID:22116936

Predictions from Badonyi M, Marsh JA. PLoS ONE. 2024;19(8):e0307312. Mechanism ranking also informed by gnomAD constraint, ClinVar, and ClinGen data.