Is BLM p.Thr1074fs (c.3220_3221insG) pathogenic?

BLM p.Thr1074fs (c.32203221insG) is classified Pathogenic in BLM (ClinVar, Multiple submitters, 2 submitters; last evaluated 2025-11-19). Absent from gnomAD; Associated with hereditary neoplastic syndrome.

What condition is associated with BLM p.Thr1074fs (c.3220_3221insG)?

BLM p.Thr1074fs (c.3220_3221insG) is associated with hereditary neoplastic syndrome, Bloom syndrome (ClinVar).

How common is BLM p.Thr1074fs (c.3220_3221insG) in the general population?

BLM p.Thr1074fs (c.3220_3221insG) is absent from gnomAD (gnomAD).

BLM p.Thr1074fs

c.3220_3221insG · rs2505534228 · VCV1729072

Pathogenic Multiple submitters

Classification

Pathogenic

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 2 submitters

Consequence

frameshift

predicted LoF

gnomAD v4.1

Not reported

no gnomAD frequency available for this variant

Conditions

hereditary neoplastic syndrome

Computational evidence

Protein change
Missense predictors do not apply to this variant type; conservation carries the signal.
Consequence	frameshift	predicted loss-of-function
NMD	predicted	premature termination codon in exon 17 of 22
Splicing
SpliceAI	—	not assessed · substitutions only
Constraint at this position
Conservation	phyloP 7.8	GERP 1.3, phastCons 1

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

Population frequency

dbSNP / gnomAD

No gnomAD frequency available for this variant. This is missing data, not an absence: the variant may or may not be present in gnomAD. Rarity (ACMG PM2) and BA1/BS1 cannot be assessed for it.

Variant & gene context

Gene: BLM
Protein: p.Thr1074fs
Coding: c.3220_3221insG
MANE Select: NM_000057
dbSNP: rs2505534228
Type: Insertion
Location: chr15:90798199 (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 1074: a β-strand

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.Thr1074Arg Uncertain significance ★★ ⚠ same residue
BLM p.Thr1074Ile Uncertain significance ★ ⚠ same residue
BLM p.Leu751fs Pathogenic/Likely pathogenic ★★ same condition
BLM p.Ser43_Asp44insTyr Uncertain significance ★★ same condition
BLM p.Thr528delinsIleAla Uncertain significance ★★ same condition
BLM c.741_742insALU Likely pathogenic ★ same condition
BLM p.Asn515Ter Likely pathogenic ★ same condition
BLM p.Asn66delinsThrLeuPheTer 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-thr1074fs (accessed [today's date]).

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