Is RB1 p.Arg7= (c.21A>G) pathogenic?

RB1 p.Arg7= (c.21A>G) is classified Benign/Likely benign in RB1 (ClinVar, Multiple submitters, 3 submitters; last evaluated 2026-06-23). Absent from gnomAD v4.1; Associated with hereditary neoplastic syndrome.

What condition is associated with RB1 p.Arg7= (c.21A>G)?

RB1 p.Arg7= (c.21A>G) is associated with hereditary neoplastic syndrome, retinoblastoma (ClinVar).

How common is RB1 p.Arg7= (c.21A>G) in the general population?

RB1 p.Arg7= (c.21A>G) is absent from gnomAD v4.1 (gnomAD).

RB1 p.Arg7=

c.21A>G · rs2138027098 · VCV1081885

Benign/Likely benign Multiple submitters

Classification

Benign/Likely benign

ClinVar

Review

Multiple submitters ★★☆☆

ClinVar · 3 submitters

gnomAD v4.1

Absent

absent from gnomAD v4.1

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 0.005	GERP -2.7, phastCons 0.37
Overall
CADD	11.11	PHRED · no single calibrated threshold — expert panels disagree

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.Arg7=
Coding: c.21A>G
MANE Select: NM_000321
dbSNP: rs2138027098
Type: single nucleotide variant
Location: chr13:48303933 (GRCh38)
Gene constraint: LOEUF 0.239 · pLI 1.00 · ClinGen HI 3/3 (gnomAD)
Structure: AlphaFold pLDDT 77.03 · 19 PDB
Residue 7: the 'disordered' region

Full RB1 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: retinoblastoma

Similar variants

RB1 p.Arg7Gln Uncertain significance ★★ ⚠ same residue
RB1 p.Arg7Gly Uncertain significance ★ ⚠ same residue
RB1 p.Arg7fs Pathogenic ★★ 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-arg7 (accessed [today's date]).

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