TLL1

Chr 4AD

tolloid like 1

Also known as: ASD6, TLL

This gene encodes a zinc-dependent metalloprotease that processes procollagen C-propeptides including chordin, pro-biglycan, and pro-lysyl oxidase, playing essential roles in cardiac development and formation of the interventricular septum. Mutations cause atrial septal defect 6, inherited in an autosomal dominant pattern. The gene shows moderate constraint against loss-of-function variants (LOEUF 0.37), suggesting some intolerance to complete protein loss.

Summary from RefSeq, OMIM, UniProt
Research Assistant →

Primary Disease Associations & Inheritance

Atrial septal defect 6MIM #613087
AD
0
Active trials
8
Pubs (1 yr)
0
P/LP submissions
P/LP missense
0.37
LOEUF
Multiple*
Mechanism· predicted
Clinical SummaryTLL1
🧬
Gene-Disease Validity (ClinGen)
congenital heart disease · ADLimited

Limited evidence — not for standalone diagnostic reporting

Population Constraint (gnomAD)
Constrained for loss-of-function variants (OE-LoF 0.24) despite low pLI — interpret in context.

Population Genetics & Constraint

gnomAD v4 — loss-of-function & missense intolerance

Moderate LoF intolerance
LoF Constraint
0.37LOEUF
pLI 0.173
Z-score 5.44
OE 0.24 (0.150.37)
Moderately constrained

More LoF-intolerant than ~75% of genes

Missense Constraint
0.94Z-score
OE missense 0.89 (0.820.96)
484 obs / 545.8 exp
Tolerant

Mild missense constraint

Observed / Expected Ratios
LoF OE0.24 (0.150.37)
00.351.4
Missense OE0.89 (0.820.96)
00.61.4
Synonymous OE1.09
01.21.6
LoF obs/exp: 14 / 59.1Missense obs/exp: 484 / 545.8Syn Z: -0.94
Curated Mechanism (G2P)Gene2Phenotype (DDG2P) ↗
limitedTLL1-related atrial septal defectOTHERAD
DN
0.7327th %ile
GOF
0.6930th %ile
LOF
0.3551th %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

TLL1 · 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.

Search ClinicalTrials.gov →
Clinical Literature
Open Research Assistant →