rs587778871

Positions:

• chr13-48456354-G-A
• chr13-48456354-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP5_Moderate

The ENST00000267163.6(RB1):​c.1960+5G>A variant causes a splice donor 5th base, intron change. The variant allele was found at a frequency of 0.00000137 in 1,461,646 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: RB1 ENST00000267163.6 splice_donor_5th_base, intron
• Scores: Splicing: ADA: 0.9999
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 4.78

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-48456354-G-A is Pathogenic according to our data. Variant chr13-48456354-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 126791.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RB1	NM_000321.3	c.1960+5G>A		splice_donor_5th_base_variant, intron_variant		ENST00000267163.6	NP_000312.2
RB1	NM_001407165.1	c.1960+5G>A		splice_donor_5th_base_variant, intron_variant			NP_001394094.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RB1	ENST00000267163.6	c.1960+5G>A		splice_donor_5th_base_variant, intron_variant		1	NM_000321.3	ENSP00000267163	P1
RB1	ENST00000643064.1	c.194+74911G>A		intron_variant				ENSP00000496005
RB1	ENST00000650461.1	c.1960+5G>A		splice_donor_5th_base_variant, intron_variant				ENSP00000497193
RB1	ENST00000480491.1			downstream_gene_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461646 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727112

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Retinoblastoma Pathogenic:1

Pathogenic, no assertion criteria provided

clinical testing

Genetic Diagnostic Laboratory, University of Pennsylvania School of Medicine

Sep 16, 2013

- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jul 08, 2022

Intronic +5 splice site variant in a gene for which loss of function is a known mechanism of disease, and splice predictors support a deleterious effect; Not observed at significant frequency in large population cohorts (gnomAD); Reported previously, as 2098+5G>A using alternate nomenclature, in at least one individual with retinoblastoma (Richter 2003); This variant is associated with the following publications: (PMID: 12541220, 25525159, 31129100) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.28
CADD	Uncertain	24
DANN	Benign	0.91

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.98
SpliceAI score (max)		0.29		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.29		Position offset: -5

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

Publications

LitVar

Other links and lift over

dbSNP: rs587778871; hg19: chr13-49030490;