13-48307377-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_000321.3(RB1):​c.235G>C​(p.Glu79Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,172 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

RB1
NM_000321.3 missense

Scores

3
15

Clinical Significance

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

Conservation

PhyloP100: 2.20

Publications

0 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 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.16095877).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
RB1NM_000321.3 linkc.235G>C p.Glu79Gln missense_variant Exon 2 of 27 ENST00000267163.6 NP_000312.2
RB1NM_001407165.1 linkc.235G>C p.Glu79Gln missense_variant Exon 2 of 27 NP_001394094.1
RB1NM_001407166.1 linkc.235G>C p.Glu79Gln missense_variant Exon 2 of 17 NP_001394095.1
RB1NM_001407167.1 linkc.235G>C p.Glu79Gln missense_variant Exon 2 of 3 NP_001394096.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
RB1ENST00000267163.6 linkc.235G>C p.Glu79Gln missense_variant Exon 2 of 27 1 NM_000321.3 ENSP00000267163.4

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461172
Hom.:
0
Cov.:
30
AF XY:
0.00
AC XY:
0
AN XY:
726938
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33456
American (AMR)
AF:
0.00
AC:
0
AN:
44716
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26112
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39558
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86242
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53406
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111568
Other (OTH)
AF:
0.00
AC:
0
AN:
60354
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

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32

ClinVar

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

Submissions by phenotype

Retinoblastoma Uncertain:1
Nov 06, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glutamic acid, which is acidic and polar, with glutamine, which is neutral and polar, at codon 79 of the RB1 protein (p.Glu79Gln). 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: 410946). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae 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.

Malignant tumor of urinary bladder Uncertain:1
Sep 10, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not provided Uncertain:1
Mar 01, 2024
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: 23516486)

Hereditary cancer-predisposing syndrome Uncertain:1
Jan 02, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.E79Q variant (also known as c.235G>C), located in coding exon 2 of the RB1 gene, results from a G to C substitution at nucleotide position 235. The glutamic acid at codon 79 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. 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
0.089
BayesDel_addAF
Benign
-0.11
T
BayesDel_noAF
Benign
-0.40
CADD
Benign
20
DANN
Uncertain
0.98
DEOGEN2
Benign
0.40
T;.;.
Eigen
Benign
-0.24
Eigen_PC
Benign
-0.091
FATHMM_MKL
Uncertain
0.77
D
LIST_S2
Benign
0.73
T;T;T
M_CAP
Benign
0.0086
T
MetaRNN
Benign
0.16
T;T;T
MetaSVM
Benign
-0.98
T
MutationAssessor
Benign
0.63
N;.;.
PhyloP100
2.2
PrimateAI
Uncertain
0.51
T
PROVEAN
Benign
-0.50
N;.;.
REVEL
Benign
0.052
Sift
Benign
0.14
T;.;.
Sift4G
Benign
0.32
T;.;.
Vest4
0.39
ClinPred
0.39
T
GERP RS
3.1
Varity_R
0.20
gMVP
0.28
Mutation Taster
=66/34
polymorphism

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: rs1060503090; hg19: chr13-48881513; API