chr13-48307290-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 4P and 3B. PM1PM2BP4_ModerateBP6

The NM_000321.3(RB1):​c.148G>C​(p.Glu50Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000249 in 1,606,052 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E50D) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

RB1
NM_000321.3 missense

Scores

6
13

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:2B:1

Conservation

PhyloP100: 4.59

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 1 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 30 uncertain in NM_000321.3
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.20796126).
BP6
Variant 13-48307290-G-C is Benign according to our data. Variant chr13-48307290-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 410937.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
RB1NM_000321.3 linkc.148G>C p.Glu50Gln missense_variant Exon 2 of 27 ENST00000267163.6 NP_000312.2 P06400A0A024RDV3
RB1NM_001407165.1 linkc.148G>C p.Glu50Gln missense_variant Exon 2 of 27 NP_001394094.1
RB1NM_001407166.1 linkc.148G>C p.Glu50Gln missense_variant Exon 2 of 17 NP_001394095.1
RB1NM_001407167.1 linkc.148G>C p.Glu50Gln 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.148G>C p.Glu50Gln missense_variant Exon 2 of 27 1 NM_000321.3 ENSP00000267163.4 P06400

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152174
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000138
AC:
2
AN:
1453878
Hom.:
0
Cov.:
30
AF XY:
0.00
AC XY:
0
AN XY:
723766
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33268
American (AMR)
AF:
0.00
AC:
0
AN:
44698
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26068
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39518
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86080
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53362
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5750
European-Non Finnish (NFE)
AF:
0.00000181
AC:
2
AN:
1105020
Other (OTH)
AF:
0.00
AC:
0
AN:
60114
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000203476), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
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
AF:
0.0000131
AC:
2
AN:
152174
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74328
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41444
American (AMR)
AF:
0.00
AC:
0
AN:
15278
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10600
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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

Genome 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
Alfa
AF:
0.0000712
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:2Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Retinoblastoma Uncertain:2
Nov 25, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. ClinVar contains an entry for this variant (Variation ID: 410937). This variant has not been reported in the literature in individuals affected with RB1-related conditions. This variant is present in population databases (no rsID available, gnomAD 0.01%). This sequence change replaces glutamic acid, which is acidic and polar, with glutamine, which is neutral and polar, at codon 50 of the RB1 protein (p.Glu50Gln). -

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 glutamic acid with glutamine at codon 50 of the RB1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, 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 been identified in 2/31388 chromosomes 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. -

Hereditary cancer-predisposing syndrome Benign:1
Jul 15, 2021
Ambry Genetics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.098
BayesDel_addAF
Uncertain
0.032
T
BayesDel_noAF
Benign
-0.19
CADD
Benign
22
DANN
Uncertain
0.99
DEOGEN2
Benign
0.36
T;.;.
Eigen
Benign
0.12
Eigen_PC
Uncertain
0.25
FATHMM_MKL
Uncertain
0.76
D
LIST_S2
Benign
0.79
T;T;T
M_CAP
Benign
0.040
D
MetaRNN
Benign
0.21
T;T;T
MetaSVM
Uncertain
0.11
D
MutationAssessor
Benign
0.55
N;.;.
PhyloP100
4.6
PrimateAI
Uncertain
0.77
T
PROVEAN
Benign
-0.54
N;.;.
REVEL
Benign
0.20
Sift
Benign
0.13
T;.;.
Sift4G
Benign
0.38
T;.;.
Polyphen
0.40
B;.;.
Vest4
0.34
MutPred
0.28
Gain of catalytic residue at P55 (P = 0.0014);Gain of catalytic residue at P55 (P = 0.0014);Gain of catalytic residue at P55 (P = 0.0014);
MVP
0.81
MPC
0.54
ClinPred
0.64
D
GERP RS
4.8
Varity_R
0.15
gMVP
0.24
Mutation Taster
=83/17
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: rs1060503085; hg19: chr13-48881426; API