rs1447082021

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP3

The NM_000321.3(RB1):​c.2066A>G​(p.Gln689Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000186 in 1,613,934 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Q689K) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 30)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

RB1
NM_000321.3 missense

Scores

5
9
5

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 8.95

Publications

3 publications found
Variant links:
Genes affected
RB1 (HGNC:9884): (RB transcriptional corepressor 1) The protein encoded by this gene is a negative regulator of the cell cycle and was the first tumor suppressor gene found. The encoded protein also stabilizes constitutive heterochromatin to maintain the overall chromatin structure. The active, hypophosphorylated form of the protein binds transcription factor E2F1. Defects in this gene are a cause of childhood cancer retinoblastoma (RB), bladder cancer, and osteogenic sarcoma. [provided by RefSeq, Jul 2008]
RB1 Gene-Disease associations (from GenCC):
  • hereditary retinoblastoma
    Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, G2P, Ambry Genetics
  • retinoblastoma
    Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
  • melanoma
    Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.771

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
RB1NM_000321.3 linkc.2066A>G p.Gln689Arg missense_variant Exon 20 of 27 ENST00000267163.6 NP_000312.2
RB1NM_001407165.1 linkc.2066A>G p.Gln689Arg missense_variant Exon 20 of 27 NP_001394094.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
RB1ENST00000267163.6 linkc.2066A>G p.Gln689Arg missense_variant Exon 20 of 27 1 NM_000321.3 ENSP00000267163.4

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152150
Hom.:
0
Cov.:
30
show subpopulations
Gnomad AFR
AF:
0.0000241
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461784
Hom.:
0
Cov.:
34
AF XY:
0.00
AC XY:
0
AN XY:
727196
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39694
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53420
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5766
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111922
Other (OTH)
AF:
0.00
AC:
0
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152150
Hom.:
0
Cov.:
30
AF XY:
0.00
AC XY:
0
AN XY:
74336
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41408
American (AMR)
AF:
0.00
AC:
0
AN:
15280
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4826
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2086
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Retinoblastoma Uncertain:2
Dec 13, 2023
All of Us Research Program, National Institutes of Health
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This missense variant replaces glutamine with arginine at codon 689 of the RB1 protein. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with RB1-related disorders in the literature. This variant has not been identified in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Oct 16, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamine, which is neutral and polar, with arginine, which is basic and polar, at codon 689 of the RB1 protein (p.Gln689Arg). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with RB1-related conditions. ClinVar contains an entry for this variant (Variation ID: 458139). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt RB1 protein function with a negative predictive value of 80%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Uncertain:1
May 21, 2023
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 29604063, 23516486, Day alan_2006_Review) -

Hereditary cancer-predisposing syndrome Uncertain:1
Nov 16, 2023
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.Q689R variant (also known as c.2066A>G), located in coding exon 20 of the RB1 gene, results from an A to G substitution at nucleotide position 2066. The glutamine at codon 689 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.22
BayesDel_addAF
Pathogenic
0.18
D
BayesDel_noAF
Uncertain
0.020
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.67
D;.
Eigen
Uncertain
0.40
Eigen_PC
Uncertain
0.50
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Benign
0.82
T;T
M_CAP
Uncertain
0.10
D
MetaRNN
Pathogenic
0.77
D;D
MetaSVM
Uncertain
0.35
D
MutationAssessor
Uncertain
2.2
M;.
PhyloP100
8.9
PrimateAI
Pathogenic
0.83
D
PROVEAN
Benign
-1.4
N;.
REVEL
Uncertain
0.64
Sift
Benign
0.67
T;.
Sift4G
Pathogenic
0.0
D;.
Polyphen
0.57
P;.
Vest4
0.74
MutPred
0.47
Gain of catalytic residue at L688 (P = 0);Gain of catalytic residue at L688 (P = 0);
MVP
0.89
MPC
0.71
ClinPred
0.96
D
GERP RS
5.5
Varity_R
0.37
gMVP
0.72
Mutation Taster
=15/85
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs1447082021; hg19: chr13-49033929; API