rs201046651

Variant names:

• chr13-48459760-A-G
• rs201046651
• NM_000321.3:c.2033A>G

Your query was ambiguous. Multiple possible variants found:

• chr13-48459760-A-G
• chr13-48459760-A-T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_000321.3(RB1):​c.2033A>G​(p.His678Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,640 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: RB1 NM_000321.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.76
• Publications: 1 publications found

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

ACMG classification

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 (MetaRNN=0.16077995).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RB1	NM_000321.3	c.2033A>G	p.His678Arg	missense_variant	Exon 20 of 27	ENST00000267163.6	NP_000312.2
RB1	NM_001407165.1	c.2033A>G	p.His678Arg	missense_variant	Exon 20 of 27		NP_001394094.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RB1	ENST00000267163.6	c.2033A>G	p.His678Arg	missense_variant	Exon 20 of 27	1	NM_000321.3	ENSP00000267163.4

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461640 Hom.: 0 Cov.: 34 AF XY: 0.00000275 AC XY: 2 AN XY: 727126

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39694

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86246

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111788

Other (OTH) AF: 0.00 AC: 0 AN: 60386

GnomAD4 genome Cov.: 30

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Retinoblastoma Uncertain:1

Nov 12, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces histidine, which is basic and polar, with arginine, which is basic and polar, at codon 678 of the RB1 protein (p.His678Arg). This variant is not present in population databases (gnomAD no frequency). 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: 567172). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is not expected to disrupt RB1 protein function with a negative predictive value of 80%. 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.

Hereditary cancer-predisposing syndrome Uncertain:1

Feb 05, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.H678R variant (also known as c.2033A>G), located in coding exon 20 of the RB1 gene, results from an A to G substitution at nucleotide position 2033. The histidine at codon 678 is replaced by arginine, an amino acid with highly similar properties. This amino acid position is not well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Based on the available evidence, the clinical significance of this variant remains unclear.

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.044	T
BayesDel_noAF	Benign	-0.17
CADD	Benign	19
DANN	Benign	0.63
DEOGEN2	Benign	0.41	T;.
Eigen	Benign	-0.36
Eigen_PC	Benign	-0.14
FATHMM_MKL	Uncertain	0.81	D
LIST_S2	Benign	0.82	T;T
M_CAP	Benign	0.042	D
MetaRNN	Benign	0.16	T;T
MetaSVM	Benign	-0.43	T
MutationAssessor	Benign	0.82	L;.
PhyloP100		1.8
PrimateAI	Uncertain	0.78	T
PROVEAN	Benign	-0.57	N;.
REVEL	Benign	0.24
Sift	Benign	1.0	T;.
Sift4G	Benign	0.76	T;.
Vest4		0.36
ClinPred		0.28	T
GERP RS		5.5
Varity_R		0.45
gMVP		0.29
Mutation Taster		=85/15	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

Other links and lift over

dbSNP: rs201046651; hg19: chr13-49033896;