chr20-37020697-T-A

Position:

• chr20-37020697-T-A

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_002895.5(RBL1):​c.2593A>T​(p.Met865Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: RBL1 NM_002895.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.54

Genes affected

RBL1 (HGNC:9893): (RB transcriptional corepressor like 1) The protein encoded by this gene is similar in sequence and possibly function to the product of the retinoblastoma 1 (RB1) gene. The RB1 gene product is a tumor suppressor protein that appears to be involved in cell cycle regulation, as it is phosphorylated in the S to M phase transition and is dephosphorylated in the G1 phase of the cell cycle. Both the RB1 protein and the product of this gene can form a complex with adenovirus E1A protein and SV40 large T-antigen, with the SV40 large T-antigen binding only to the unphosphorylated form of each protein. In addition, both proteins can inhibit the transcription of cell cycle genes containing E2F binding sites in their promoters. Due to the sequence and biochemical similarities with the RB1 protein, it is thought that the protein encoded by this gene may also be a tumor suppressor. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RBL1	NM_002895.5	c.2593A>T	p.Met865Leu	missense_variant	18/22	ENST00000373664.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RBL1	ENST00000373664.8	c.2593A>T	p.Met865Leu	missense_variant	18/22	1	NM_002895.5	P1
RBL1	ENST00000344359.7	c.2593A>T	p.Met865Leu	missense_variant	18/21	1

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 31

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 22, 2023

The c.2593A>T (p.M865L) alteration is located in exon 18 (coding exon 18) of the RBL1 gene. This alteration results from a A to T substitution at nucleotide position 2593, causing the methionine (M) at amino acid position 865 to be replaced by a leucine (L). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.73
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Uncertain	24
DANN	Benign	0.97
DEOGEN2	Uncertain	0.54	D;.
Eigen	Benign	0.090
Eigen_PC	Uncertain	0.26
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;D
M_CAP	Benign	0.066	D
MetaRNN	Uncertain	0.69	D;D
MetaSVM	Uncertain	-0.061	T
MutationAssessor	Benign	1.9	L;L
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-2.7	D;D
REVEL	Pathogenic	0.68
Sift	Uncertain	0.010	D;T
Sift4G	Benign	0.11	T;T
Polyphen		0.064	B;B
Vest4		0.72
MutPred		0.72		Gain of methylation at K866 (P = 0.0771);Gain of methylation at K866 (P = 0.0771);
MVP		0.88
MPC		0.23
ClinPred		0.95	D
GERP RS		5.3
Varity_R		0.87
gMVP		0.58

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr20-35649100;