chr13-48303758-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.-155G>C variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000095 in 1,053,094 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 9.5e-7 ( 0 hom. )

Consequence

RB1
NM_000321.3 5_prime_UTR

Scores

2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.02

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-DT (HGNC:42778): (RB1 divergent transcript)

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 (BayesDel_noAF=-0.29).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
RB1NM_000321.3 linkc.-155G>C 5_prime_UTR_variant Exon 1 of 27 ENST00000267163.6 NP_000312.2 P06400A0A024RDV3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
RB1ENST00000267163.6 linkc.-155G>C 5_prime_UTR_variant Exon 1 of 27 1 NM_000321.3 ENSP00000267163.4 P06400

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
9.50e-7
AC:
1
AN:
1053094
Hom.:
0
Cov.:
14
AF XY:
0.00000193
AC XY:
1
AN XY:
519178
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:
20688
American (AMR)
AF:
0.00
AC:
0
AN:
15330
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
18440
East Asian (EAS)
AF:
0.00
AC:
0
AN:
26502
South Asian (SAS)
AF:
0.00
AC:
0
AN:
59582
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
30668
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
3206
European-Non Finnish (NFE)
AF:
0.00000120
AC:
1
AN:
833536
Other (OTH)
AF:
0.00
AC:
0
AN:
45142
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), 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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Retinoblastoma Uncertain:1
Apr 06, 2018
Illumina Laboratory Services, Illumina
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.29
CADD
Benign
19
DANN
Benign
0.97
PhyloP100
2.0
PromoterAI
-0.13
Neutral

Splicing

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

Publications

Other links and lift over

dbSNP: rs1952049136; hg19: chr13-48877894; API