Is DNMT3A p.Trp409Ter (c.1227G>A) pathogenic?

DNMT3A p.Trp409Ter (c.1227G>A) is classified Pathogenic in DNMT3A (ClinVar, Single submitter, 1 submitter; last evaluated 2024-03-25). Very rare (popmax 0.000339%, nfe); Associated with Tatton-Brown-Rahman overgrowth syndrome.

What condition is associated with DNMT3A p.Trp409Ter (c.1227G>A)?

DNMT3A p.Trp409Ter (c.1227G>A) is associated with Tatton-Brown-Rahman overgrowth syndrome (ClinVar).

How common is DNMT3A p.Trp409Ter (c.1227G>A) in the general population?

DNMT3A p.Trp409Ter (c.1227G>A) is very rare (popmax 0.000339%, nfe) (gnomAD).

DNMT3A p.Trp409Ter

c.1227G>A · VCV3608977

Pathogenic Single submitter

Classification

Pathogenic

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

Consequence

nonsense (stop-gain)

predicted LoF

gnomAD v4.1

Rare

very rare (popmax 0.000339%, nfe)

Conditions

Tatton-Brown-Rahman overgrowth syndrome

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	nonsense (stop-gain)	predicted loss-of-function in a haploinsufficient gene (ClinGen)
NMD	predicted	premature termination codon in exon 10 of 23
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 5.9	GERP 1.7, phastCons 1
Overall
CADD	39.0	PHRED · no single calibrated threshold — expert panels disagree

Predicted loss-of-function is descriptive, not an applied PVS1 code.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000339% European (non-Finnish) · 4/1,179,976 alleles

Filtering AF 7.9e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 5.4e-05%

Overall 0.000274% 4/1,461,320 alleles · very rare

Rarity supports pathogenicity (ACMG PM2); frequency above a disease-specific BA1/BS1 threshold argues against it. A variant frequent in one ancestry group can be near-absent in others, so a single global figure can mislead.

Variant & gene context

Gene: DNMT3A
Protein: p.Trp409Ter
Coding: c.1227G>A
MANE Select: NM_022552
Type: single nucleotide variant
Location: chr2:25246672 (GRCh38)
Gene constraint: LOEUF 1.998 · pLI <0.01 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 73.97 · 47 PDB
Residue 409: an α-helix

Full DNMT3A gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

Tatton-Brown-Rahman overgrowth syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Similar variants

DNMT3A c.1667+1G>A Likely pathogenic ★★ same condition
DNMT3A c.1937-2A>G Pathogenic ★★ same condition
DNMT3A c.2478+1G>A Pathogenic/Likely pathogenic ★★ same condition
DNMT3A c.2479-1G>A Likely pathogenic ★★ same condition
DNMT3A p.Arg143Ter Pathogenic ★★ same condition
DNMT3A p.Arg320Ter Pathogenic/Likely pathogenic ★★ same condition
DNMT3A p.Arg598Ter Pathogenic/Likely pathogenic ★★ same condition
DNMT3A p.Arg688His Pathogenic/Likely pathogenic ★★ same condition

Built on 18 open, versioned datasets — ClinVar, gnomAD, AlphaMissense, REVEL, ClinGen & more — plus Sugi Variant's own cross-source analysis. Source data 2026-01–2026-10, ClinVar 2026-10. Full sources & versions →

Cite Sugi Variant

Gür T. Sugi Variant: A Deterministic Per-Variant Germline Reference from a Knowledge Graph for Humans and AI Agents. 2026. doi:10.5281/zenodo.21509445. This variant: https://sugi.bio/variant/dnmt3a-p-trp409ter (accessed [today's date]).

Preprint & method: sugi.bio/variant/method Machine-readable: this page as Markdown