13-48380200-TA-T

Position:

• chr13-48380200-TA-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000321.3(RB1):​c.1458del​(p.Leu486PhefsTer9) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: RB1 NM_000321.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.436

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 Pathogenic. Variant got 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-48380200-TA-T is Pathogenic according to our data. Variant chr13-48380200-TA-T is described in ClinVar as [Pathogenic]. Clinvar id is 458123.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr13-48380200-TA-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RB1	NM_000321.3	c.1458del	p.Leu486PhefsTer9	frameshift_variant	16/27	ENST00000267163.6
RB1	NM_001407165.1	c.1458del	p.Leu486PhefsTer9	frameshift_variant	16/27
RB1	NM_001407166.1	c.1458del	p.Leu486PhefsTer9	frameshift_variant	16/17

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RB1	ENST00000267163.6	c.1458del	p.Leu486PhefsTer9	frameshift_variant	16/27	1	NM_000321.3	P1
RB1	ENST00000650461.1	c.1458del	p.Leu486PhefsTer9	frameshift_variant	16/27

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Retinoblastoma Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 28, 2019

This sequence change creates a premature translational stop signal (p.Leu486Phefs*9) in the RB1 gene. It is expected to result in an absent or disrupted protein product. This variant is not present in population databases (ExAC no frequency). This variant has been reported in individuals in the Leiden Open-source Variation Database (PMID: 21520333). ClinVar contains an entry for this variant (Variation ID: 458123). Loss-of-function variants in RB1 are known to be pathogenic (PMID: 17096365). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1555286611; hg19: chr13-48954336;