Is RB1 p.Pro674Arg (c.2021C>G) pathogenic?

RB1 p.Pro674Arg (c.2021C>G) is classified Uncertain significance in RB1 (ClinVar, Single submitter, 1 submitter; last evaluated 2025-01-17). AlphaMissense: likely benign (0.1129); Absent from gnomAD v4.1; Associated with retinoblastoma.

What condition is associated with RB1 p.Pro674Arg (c.2021C>G)?

RB1 p.Pro674Arg (c.2021C>G) is associated with retinoblastoma (ClinVar).

How common is RB1 p.Pro674Arg (c.2021C>G) in the general population?

RB1 p.Pro674Arg (c.2021C>G) is absent from gnomAD v4.1 (gnomAD).

How is Retinoblastoma inherited?

Typically Autosomal dominant, Not applicable (Orphanet). A genetic counselor can assess individual risk for a family.

What do computational predictors say about RB1 p.Pro674Arg (c.2021C>G)?

AlphaMissense predicts likely benign (score 0.1129) — an in-silico prediction, not a clinical call.

RB1 p.Pro674Arg

c.2021C>G · rs2138336118 · VCV2090570

Uncertain significance Single submitter

Classification

Uncertain significance

ClinVar

Review

Single submitter ★☆☆☆

ClinVar · 1 submitter

AlphaMissense

likely benign

0.1129 · ACMG-weighted

gnomAD v4.1

Absent

absent from gnomAD v4.1

Missense predictors

0/2 damaging

AlphaMissense, SaProt · REVEL indeterminate

Conditions

retinoblastoma

Computational evidence

Protein change
AlphaMissense	0.1129	likely benign
REVEL	0.573	indeterminate
SaProt	LLR -5.81	tolerated
⇒ AlphaMissense and SaProt both call this tolerated; REVEL is indeterminate.
Splicing
SpliceAI	—	not assessed · no allele here is in the release
Constraint at this position
Conservation	phyloP 6	GERP 1.8, phastCons 1
Regional constraint	o/e 0.39	unconstrained · MANE · 4,086 bp · p 7e-08 · regional, not allelic
Overall
CADD	24.1	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

Absent from gnomAD v4.1. Not observed in any sequenced alleles — a rarity signal (ACMG PM2-supporting), not evidence of pathogenicity on its own.

Variant & gene context

Gene: RB1
Protein: p.Pro674Arg
Coding: c.2021C>G
MANE Select: NM_000321
dbSNP: rs2138336118
Type: single nucleotide variant
Location: chr13:48459748 (GRCh38)
Gene constraint: LOEUF 0.239 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 77.03 · 19 PDB
Residue 674: the 'pocket; binds t and e1a' region; the 'domain b' region

Full RB1 gene report on Sugi Atlas → Gene function, pathways, protein structure, interactions & more

Disease context

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

For Retinoblastoma (Orphanet):

Inheritance: Autosomal dominant, Not applicable
Onset: Antenatal, Childhood, Infancy
Prevalence: <1 / 1 000 000 (Europe)

Similar variants

RB1 p.Pro674Ser Uncertain significance ★★ ⚠ same residue
RB1 p.Pro674= Benign/Likely benign ★★ same residue
RB1 p.Pro674Thr Uncertain significance ★ ⚠ same residue
RB1 c.1049+1G>A Pathogenic/Likely pathogenic ★★ same condition
RB1 c.1049+1G>T Pathogenic/Likely pathogenic ★★ same condition
RB1 c.1049+3A>G Pathogenic/Likely pathogenic ★★ same condition
RB1 c.1050-2A>G Pathogenic/Likely pathogenic ★★ same condition
RB1 c.1128-1G>A 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/rb1-p-pro674arg (accessed [today's date]).

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