Is BLM p.Asn405Ser (c.1214A>G) pathogenic?

BLM p.Asn405Ser (c.1214A>G) is classified Conflicting classifications of pathogenicity in BLM (ClinVar, Conflicting submitters, 2 submitters; last evaluated 2024-04-15). AlphaMissense: likely benign (0.0956); Very rare (popmax 0.000169%, nfe); Associated with Bloom syndrome.

What condition is associated with BLM p.Asn405Ser (c.1214A>G)?

BLM p.Asn405Ser (c.1214A>G) is associated with Bloom syndrome, hereditary neoplastic syndrome (ClinVar).

How common is BLM p.Asn405Ser (c.1214A>G) in the general population?

BLM p.Asn405Ser (c.1214A>G) is very rare (popmax 0.000169%, nfe) (gnomAD).

How is Bloom syndrome inherited?

Typically Autosomal recessive (Orphanet). A genetic counselor can assess individual risk for a family.

What do computational predictors say about BLM p.Asn405Ser (c.1214A>G)?

AlphaMissense predicts likely benign (score 0.0956) — an in-silico prediction, not a clinical call.

BLM p.Asn405Ser

c.1214A>G · rs752223894 · VCV844912

Conflicting classifications of pathogenicity Conflicting submitters

Classification

Conflicting classifications of pathogenicity

ClinVar

Review

Conflicting submitters ★☆☆☆

ClinVar · 2 submitters

AlphaMissense

likely benign

0.0956 · ACMG-weighted

gnomAD v4.1

Rare

very rare (popmax 0.000169%, nfe)

Missense predictors

0/3 damaging

AlphaMissense, REVEL, SaProt

Conditions

Bloom syndrome

Computational evidence

Protein change
AlphaMissense	0.0956	likely benign
REVEL	0.094	moderately benign-leaning
SaProt	LLR -6.56	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 5.2	GERP 2.8, phastCons 0.75
Regional constraint	o/e 0.96	unconstrained · MANE · 16 kb · p 0.23 · regional, not allelic
Overall
CADD	17.9	PHRED · no single calibrated threshold — expert panels disagree

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

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.000169% European (non-Finnish) · 2/1,180,014 alleles

Filtering AF 2.8e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 1.1e-05%

Overall 0.000137% 2/1,461,784 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.Asn405Ser
Coding: c.1214A>G
MANE Select: NM_000057
dbSNP: rs752223894
Type: single nucleotide variant
Location: chr15:90760273 (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 405: an α-helix; the 'necessary for interaction with spidr' region; the 'necessary for dimerization and homooligomerization' region

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

Disease context

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

Also linked: hereditary neoplastic syndrome

For Bloom syndrome (Orphanet):

Inheritance: Autosomal recessive
Onset: Antenatal, Neonatal
Prevalence: 1-9 / 100 000 (Specific population)

Similar variants

BLM p.Asn405Ile 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-asn405ser (accessed [today's date]).

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