chr13-48465104-C-T

Position:

• chr13-48465104-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000321.3(RB1):​c.2318C>T​(p.Ser773Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,744 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: RB1 NM_000321.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:2 O:1
• Conservation: PhyloP100: 7.57

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 Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a region_of_interest Domain C; mediates interaction with E4F1 (size 157) in uniprot entity RB_HUMAN there are 8 pathogenic changes around while only 0 benign (100%) in NM_000321.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.85

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RB1	NM_000321.3	c.2318C>T	p.Ser773Phe	missense_variant	22/27	ENST00000267163.6	NP_000312.2
RB1	NM_001407165.1	c.2318C>T	p.Ser773Phe	missense_variant	22/27		NP_001394094.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RB1	ENST00000267163.6	c.2318C>T	p.Ser773Phe	missense_variant	22/27	1	NM_000321.3	ENSP00000267163.4
RB1	ENST00000650461.1	c.2318C>T	p.Ser773Phe	missense_variant	22/27			ENSP00000497193.1
RB1	ENST00000643064.1	c.192+83661C>T		intron_variant				ENSP00000496005.1

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251378 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135892

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000653

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461744 Hom.: 0 Cov.: 35 AF XY: 0.00000275 AC XY: 2 AN XY: 727182

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: 0.0000232

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 29

Alfa AF: 0.000111 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Retinoblastoma Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 17, 2023

This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 773 of the RB1 protein (p.Ser773Phe). This variant is present in population databases (rs267603841, gnomAD 0.006%). 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: 79393). 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 expected to disrupt RB1 protein function. 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. -

Retinal dystrophy Uncertain:1

Uncertain significance, no assertion criteria provided

clinical testing

Institute of Human Genetics, Univ. Regensburg, Univ. Regensburg

Jan 01, 2022

- -

not specified Other:1

not provided, no classification provided

reference population

ITMI

Sep 19, 2013

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.83
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Pathogenic	0.30
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.84	D;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.85	D;D
MetaSVM	Uncertain	0.39	D
MutationAssessor	Benign	1.7	L;.
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-3.5	D;.
REVEL	Pathogenic	0.80
Sift	Uncertain	0.016	D;.
Sift4G	Uncertain	0.0030	D;.
Polyphen		1.0	D;.
Vest4		0.88
MutPred		0.50		Gain of catalytic residue at P776 (P = 2e-04);Gain of catalytic residue at P776 (P = 2e-04);
MVP		0.94
MPC		1.4
ClinPred		0.95	D
GERP RS		5.5
Varity_R		0.63
gMVP		0.65

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

LitVar

Other links and lift over

dbSNP: rs267603841; hg19: chr13-49039240; COSMIC: COSV57299741;