TGIF1

Chr 18AD

TGFB induced factor homeobox 1

Also known as: HPE4, TGIF

TGIF1 encodes a homeodomain transcription factor that represses retinoid X receptor signaling and SMAD2-mediated transcription, playing a critical role in forebrain development and ventral midline formation. Mutations cause holoprosencephaly type 4, a structural brain malformation affecting midline forebrain development, with autosomal dominant inheritance. The gene is not highly constrained against loss-of-function variants, consistent with its role in a dominant developmental disorder.

Summary from RefSeq, OMIM, UniProt
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Primary Disease Associations & Inheritance

Holoprosencephaly 4MIM #142946
AD
0
Active trials
17
Pubs (1 yr)
149
P/LP submissions
2%
P/LP missense
0.91
LOEUF
LOF
Mechanism· G2P
Clinical SummaryTGIF1
Population Constraint (gnomAD)
Low constraint (pLI 0.01) — loss-of-function variants are relatively tolerated in the population.
📋
ClinVar Variants
143 unique Pathogenic / Likely Pathogenic· 88 VUS of 335 total submissions
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GeneReview available — TGIF1
Authoritative clinical overview · Recommended first read
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Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Tolerant — LoF & missense variants common in population
LoF Constraint
0.91LOEUF
pLI 0.010
Z-score 1.78
OE 0.43 (0.230.91)
Tolerant

Typical tolerance to LoF variation

Missense Constraint
0.18Z-score
OE missense 0.97 (0.871.08)
225 obs / 232.6 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.43 (0.230.91)
00.351.4
Missense OE0.97 (0.871.08)
00.61.4
Synonymous OE1.08
01.21.6
LoF obs/exp: 5 / 11.5Missense obs/exp: 225 / 232.6Syn Z: -0.65
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
definitiveTGIF1-related holoprosencephalyLOFAD
DN
0.6064th %ile
GOF
0.4184th %ile
LOF
0.60top 25%

The highest-scoring mechanism for this gene is loss-of-function (haploinsufficiency).

LOF1 literature citation

Literature Evidence

LOFFunctional analysis of mutations in TGIF associated with holoprosencephalyPMID:16962354

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

ClinVar Variant Classifications

335 submitted variants in ClinVar

Classification Summary

Pathogenic133
Likely Pathogenic10
VUS88
Likely Benign50
Benign37
Conflicting7
133
Pathogenic
10
Likely Pathogenic
88
VUS
50
Likely Benign
37
Benign
7
Conflicting

Curated Variants Distribution

Classified variants from ClinVar · 5 ACMG categories

ClassificationLoFMissense + InframeNon-codingSynonymousTotal
Pathogenic
1
2
130
0
133
Likely Pathogenic
3
1
6
0
10
VUS
1
63
24
0
88
Likely Benign
0
5
22
23
50
Benign
0
3
30
4
37
Conflicting
7
Total57421227325

LoF = frameshift, stop gained/lost, canonical splice · Counts from ClinVar esearch · Updated hourly

View in ClinVar →

Protein Context — Lollipop Plot

TGIF1 · 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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Clinical Literature
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