Is NBN p.Pro427= (c.1281A>G) pathogenic?

NBN p.Pro427= (c.1281A>G) is classified Likely benign in NBN (ClinVar, Multiple submitters, 3 submitters; last evaluated 2025-07-10). Very rare (popmax 0.00167%, amr); Associated with hereditary neoplastic syndrome.

What condition is associated with NBN p.Pro427= (c.1281A>G)?

NBN p.Pro427= (c.1281A>G) is associated with hereditary neoplastic syndrome, Nijmegen breakage syndrome (ClinVar).

How common is NBN p.Pro427= (c.1281A>G) in the general population?

NBN p.Pro427= (c.1281A>G) is very rare (popmax 0.00167%, amr) (gnomAD).

NBN p.Pro427=

c.1281A>G · rs1554559167 · VCV492087

Likely benign Multiple submitters

Classification

Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Rare

very rare (popmax 0.00167%, amr)

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 -0.17	GERP -2.3
Overall
CADD	4.816	PHRED · no single calibrated threshold — expert panels disagree

Population frequency

gnomAD v4.1 · exomes + genomes

Grpmax group 0.00167% Admixed American · 1/59,996 alleles

Filtering AF 6.8e-05% ClinGen BA1/BS1 input FAF95, joint · FAF99 1.9e-05%

Overall 0.000248% 4/1,613,782 alleles · very rare

Ancestry group	Frequency	1 in
Admixed Americangrpmax	0.00167%	59,996
European (non-Finnish)	0.000254%	393,278

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: NBN
Protein: p.Pro427=
Coding: c.1281A>G
MANE Select: NM_057091 · reported on NM_002485
dbSNP: rs1554559167
Type: single nucleotide variant
Location: chr8:89955399 (GRCh38)
Structure: AlphaFold pLDDT 75.83 · 5 PDB

Full NBN 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: Nijmegen breakage syndrome

Similar variants

NBN p.Pro427Arg Conflicting classifications of pathogenicity ★ ⚠ same residue
NBN p.Pro427Ser Uncertain significance ★ ⚠ same residue
NBN p.Pro427Thr Conflicting classifications of pathogenicity ★ ⚠ same residue
NBN c.1124+1G>C Likely pathogenic ★★ same condition
NBN c.1124+2T>G Likely pathogenic ★★ same condition
NBN c.1397+2T>A Likely pathogenic ★★ same condition
NBN c.171+1G>A Likely pathogenic ★★ same condition
NBN c.172-1G>T 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/nbn-p-pro427 (accessed [today's date]).

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