NM_000321.3:c.898A>C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 0P and 6B. BP4_StrongBP6BS2_Supporting

The NM_000321.3(RB1):c.898A>C(p.Met300Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000446 in 1,569,126 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M300T) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000035 ( 0 hom. )

Consequence

RB1
NM_000321.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:2

Conservation

PhyloP100: 1.56

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 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

RB1 links:

LOC112268118 (HGNC:):

LOC112268118 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -6 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.0569942).

BP6

Variant 13-48364930-A-C is Benign according to our data. Variant chr13-48364930-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 410938.

BS2

High AC in GnomAdExome4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RB1	NM_000321.3 link	c.898A>C	p.Met300Leu	missense_variant	Exon 9 of 27	ENST00000267163.6	NP_000312.2	P06400A0A024RDV3
RB1	NM_001407165.1 link	c.898A>C	p.Met300Leu	missense_variant	Exon 9 of 27		NP_001394094.1
RB1	NM_001407166.1 link	c.898A>C	p.Met300Leu	missense_variant	Exon 9 of 17		NP_001394095.1
LOC112268118	XR_002957522.2 link	n.168T>G		non_coding_transcript_exon_variant	Exon 3 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RB1	ENST00000267163.6 link	c.898A>C	p.Met300Leu	missense_variant	Exon 9 of 27	1	NM_000321.3	ENSP00000267163.4		P06400

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152184

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000516

AC:

AN:

193920

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.0000906

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000353

AC:

AN:

1416942

Hom.:

Cov.:

AF XY:

0.00000713

AC XY:

AN XY:

701190

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

31892

American (AMR)

AF:

0.00

AC:

AN:

41470

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25350

East Asian (EAS)

AF:

0.00

AC:

AN:

37466

South Asian (SAS)

AF:

0.00

AC:

AN:

81512

European-Finnish (FIN)

AF:

0.00

AC:

AN:

50422

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5536

European-Non Finnish (NFE)

AF:

0.00000461

AC:

AN:

1085026

Other (OTH)

AF:

0.00

AC:

AN:

58268

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.465

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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

AF:

0.0000131

AC:

AN:

152184

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74350

show subpopulations

African (AFR)

AF:

0.0000483

AC:

AN:

41446

American (AMR)

AF:

0.00

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3462

East Asian (EAS)

AF:

0.00

AC:

AN:

5202

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68028

Other (OTH)

AF:

0.00

AC:

AN:

2094

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.550

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.0000113

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:2

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Retinoblastoma

Uncertain:2Benign:1

Dec 13, 2023

All of Us Research Program, National Institutes of Health

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This missense variant replaces methionine with leucine at codon 300 of the RB1 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with RB1-related disorders in the literature. This variant has been identified in 1/193920 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Jan 29, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jul 18, 2024

St. Jude Molecular Pathology, St. Jude Children's Research Hospital

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The RB1 c.898A>C (p.Met300Leu) missense change has a maximum subpopulation frequency of 0.009% in gnomAD v2.1.1 (https://gnomad.broadinstitute.org). The in silico tool REVEL predicts a benign effect on protein function, but to our knowledge this prediction has not been confirmed by functional studies. To our knowledge, this variant has not been reported in individuals with retinoblastoma. In summary, the evidence currently available is insufficient to determine the clinical significance of this variant. It has therefore been classified as of uncertain significance. -

not provided

Uncertain:1

Sep 01, 2024

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 23516486) -

Hereditary cancer-predisposing syndrome

Benign:1

Apr 25, 2024

Ambry Genetics

Significance:Benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.080

BayesDel_addAF

Benign

-0.19

BayesDel_noAF

Benign

-0.31

CADD

Benign

(source)

DANN

Benign

0.76

DEOGEN2

Benign

0.28

T;.

Eigen

Benign

-0.64

Eigen_PC

Benign

-0.31

FATHMM_MKL

Benign

0.61

LIST_S2

Benign

0.74

T;T

M_CAP

Benign

0.013

MetaRNN

Benign

0.057

T;T

MetaSVM

Benign

-0.74

MutationAssessor

Benign

-2.2

N;.

PhyloP100

1.6

PrimateAI

Uncertain

0.56

PROVEAN

Benign

0.48

N;.

REVEL

Benign

0.17

Sift

Benign

1.0

T;.

Sift4G

Benign

1.0

T;.

Polyphen

0.0

B;.

Vest4

0.26

MutPred

0.44

Gain of catalytic residue at S302 (P = 5e-04);Gain of catalytic residue at S302 (P = 5e-04);

MVP

0.59

MPC

0.41

ClinPred

0.072

GERP RS

4.3

Varity_R

0.27

gMVP

0.54

Mutation Taster

=93/7

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over