Is BLM p.Thr446= (c.1338A>G) pathogenic?

BLM p.Thr446= (c.1338A>G) is classified Likely benign in BLM (ClinVar, Multiple submitters, 2 submitters; last evaluated 2026-01-28). Ultra-rare (popmax 0.033%, mid); Associated with hereditary neoplastic syndrome.

What condition is associated with BLM p.Thr446= (c.1338A>G)?

BLM p.Thr446= (c.1338A>G) is associated with hereditary neoplastic syndrome, Bloom syndrome (ClinVar).

How common is BLM p.Thr446= (c.1338A>G) in the general population?

BLM p.Thr446= (c.1338A>G) is ultra-rare (popmax 0.033%, mid) (gnomAD).

BLM p.Thr446=

c.1338A>G · rs2151158038 · VCV1122610

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

gnomAD v4.1

Rare

ultra-rare (popmax 0.033%, mid)

Conditions

hereditary neoplastic syndrome

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP -2	GERP -5.3
Overall
CADD	0.321	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.033% Middle Eastern · 2/6,062 alleles

Filtering AF 0.00582% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.00242%

Overall 0.000124% 2/1,614,192 alleles · ultra-rare exomes 2/1,461,848 · genomes 0/152,344 · joint denominator

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: BLM
Protein: p.Thr446=
Coding: c.1338A>G
MANE Select: NM_000057
dbSNP: rs2151158038
Type: single nucleotide variant
Location: chr15:90760711 (GRCh38)
Gene constraint: LOEUF 0.847 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 61.10 · 16 PDB
Residue 446: the 'necessary for interaction with spidr' region

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

Disease context

hereditary neoplastic syndrome — disease report on Sugi Atlas → Associated genes, phenotypes, clinical trials & treatments

Also linked: Bloom syndrome

Similar variants

BLM p.Thr446Ile Uncertain significance ★★ ⚠ same residue
BLM p.Thr446Lys Uncertain significance ★★ ⚠ same residue
BLM p.Thr446Ala Uncertain significance ★ ⚠ same residue
BLM p.Thr446Pro Uncertain significance ★ ⚠ same residue
BLM p.Thr446Ser Uncertain significance ★ ⚠ same residue
BLM c.1087+1G>A Likely pathogenic ★★ same condition
BLM c.1088-1G>A Likely pathogenic ★★ same condition
BLM c.1220+2T>C 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/blm-p-thr446 (accessed [today's date]).

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