Is BLM p.Leu1396= (c.4186T>C) pathogenic?

BLM p.Leu1396= (c.4186T>C) is classified Benign/Likely benign in BLM (ClinVar, Multiple submitters, 5 submitters; last evaluated 2026-01-26). Ultra-rare (popmax 0.0512%, eas); Associated with hereditary neoplastic syndrome.

What condition is associated with BLM p.Leu1396= (c.4186T>C)?

BLM p.Leu1396= (c.4186T>C) is associated with hereditary neoplastic syndrome, Bloom syndrome (ClinVar).

How common is BLM p.Leu1396= (c.4186T>C) in the general population?

BLM p.Leu1396= (c.4186T>C) is ultra-rare (popmax 0.0512%, eas) (gnomAD).

BLM p.Leu1396=

c.4186T>C · rs376734461 · VCV236820

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 5 submitters

gnomAD v4.1

Rare

ultra-rare (popmax 0.0512%, eas)

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 -4.9	GERP -5.1
Overall
CADD	8.324	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0512% East Asian · 23/44,882 alleles

Filtering AF 0.035% ClinGen BA1/BS1 input FAF95, joint · FAF99 0.0296%

Overall 0.00328% 53/1,614,158 alleles · ultra-rare

Ancestry group	Frequency	1 in
East Asiangrpmax	0.0512%	1,951
South Asian	0.0143%	7,006
Remaining individualsnot grpmax-eligible	0.0128%	7,813
African / African-American	0.0107%	9,380
European (non-Finnish)	8.47e-05%	1,180,016

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.Leu1396=
Coding: c.4186T>C
MANE Select: NM_000057
dbSNP: rs376734461
Type: single nucleotide variant
Location: chr15:90815211 (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 1396: the 'disordered' 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.Leu1396Trp 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
BLM c.1220+2T>G Likely pathogenic ★★ same condition
BLM c.1882+2T>C Likely pathogenic ★★ same condition
BLM c.2074+1G>T Likely pathogenic ★★ same condition
BLM c.2075-1G>A 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-leu1396 (accessed [today's date]).

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