Is BLM p.Asn66Ile (c.197A>T) pathogenic?

BLM p.Asn66Ile (c.197A>T) is classified Uncertain significance in BLM (ClinVar, Single submitter, 1 submitter; last evaluated 2024-11-30). AlphaMissense: likely benign (0.1998); Very rare (popmax 0.0011%, sas); Associated with hereditary neoplastic syndrome.

What condition is associated with BLM p.Asn66Ile (c.197A>T)?

BLM p.Asn66Ile (c.197A>T) is associated with hereditary neoplastic syndrome (ClinVar).

How common is BLM p.Asn66Ile (c.197A>T) in the general population?

BLM p.Asn66Ile (c.197A>T) is very rare (popmax 0.0011%, sas) (gnomAD).

What do computational predictors say about BLM p.Asn66Ile (c.197A>T)?

AlphaMissense predicts likely benign (score 0.1998) — an in-silico prediction, not a clinical call.

BLM p.Asn66Ile

c.197A>T · VCV3480911

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1998 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.0011%, sas)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

hereditary neoplastic syndrome

Computational evidence

Protein change
AlphaMissense	0.1998	likely benign
REVEL	0.151	moderately benign-leaning
SaProt	LLR -7.44	tolerated
⇒ AlphaMissense, REVEL and SaProt all call this tolerated.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 3	GERP -0.99, phastCons 1
Regional constraint	o/e 0.96	unconstrained · MANE · 16 kb · p 0.23 · regional, not allelic
Overall
CADD	17.44	PHRED · no single calibrated threshold — expert panels disagree

ClinVar classifies this uncertain; the computational predictors unanimously lean tolerated — a triage signal, not a reclassification

AlphaMissense carries the ACMG weight for missense; REVEL and SaProt are independent agreement signals.

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.0011% South Asian · 1/91,066 alleles

Overall 6.85e-05% 1/1,460,494 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: BLM
Protein: p.Asn66Ile
Coding: c.197A>T
MANE Select: NM_000057
Type: single nucleotide variant
Location: chr15:90749465 (GRCh38)
Gene constraint: LOEUF 0.847 · pLI <0.01 · ClinGen HI gene assoc. with recessive phenotype (gnomAD)
Structure: AlphaFold pLDDT 61.10 · 16 PDB

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

Similar variants

BLM p.Asn66Ser Uncertain significance ★★ ⚠ same residue
BLM p.Asn66= Likely benign ★★ same residue
BLM p.Asn66Asp Uncertain significance ★ ⚠ same residue
BLM c.2075-1G>A Likely pathogenic ★★ same condition
BLM c.2193+1G>A Pathogenic/Likely pathogenic ★★ same condition
BLM c.2308-2A>G Pathogenic/Likely pathogenic ★★ same condition
BLM c.2407-2A>G Likely pathogenic ★★ same condition
BLM c.2555+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-asn66ile (accessed [today's date]).

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