Genetic Variant RCBTB2:p.Arg338Gln (chr13-48502828-C-T) – ACMG Classification: Uncertain_significance (2 pts)

Variant summary

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

The NM_001268.4(RCBTB2):c.1013G>A(p.Arg338Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000127 in 1,614,050 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000059 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00013 ( 0 hom. )

Consequence

RCBTB2
NM_001268.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 7.57

Variant links:

Genes affected

RCBTB2 (HGNC:1914): (RCC1 and BTB domain containing protein 2) This gene encodes a protein containing two C-terminal BTB/POZ domains that is related to regulator of chromosome condensation (RCC). The encoded protein may act as a guanine nucleotide exchange factor. This gene is observed to be lost or underexpressed in prostate cancers. There is a pseudogene of this gene on chromosome 10. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2013]

RCBTB2 links:

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 links:

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ACMG classification

Classification made for transcript

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 rank	MANE	Protein	UniProt
RCBTB2	NM_001268.4 link	c.1013G>A	p.Arg338Gln	missense_variant	Exon 11 of 15	ENST00000344532.8	NP_001259.1	O95199-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RCBTB2	ENST00000344532.8 link	c.1013G>A	p.Arg338Gln	missense_variant	Exon 11 of 15	1	NM_001268.4	ENSP00000345144.3		O95199-1

Frequencies

GnomAD3 genomes

AF:

0.0000591

AC:

AN:

152180

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.000118

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000517

AC:

AN:

251254

Hom.:

AF XY:

0.0000515

AC XY:

AN XY:

135796

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000109

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000880

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000134

AC:

196

AN:

1461870

Hom.:

Cov.:

AF XY:

0.000135

AC XY:

AN XY:

727232

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.000171

Gnomad4 OTH exome

AF:

0.0000497

GnomAD4 genome

AF:

0.0000591

AC:

AN:

152180

Hom.:

Cov.:

AF XY:

0.0000538

AC XY:

AN XY:

74350

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000118

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000180

Hom.:

Bravo

AF:

0.0000680

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000259

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000116

AC:

ExAC

AF:

0.0000412

AC:

EpiCase

AF:

0.000164

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Mar 14, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1013G>A (p.R338Q) alteration is located in exon 11 (coding exon 8) of the RCBTB2 gene. This alteration results from a G to A substitution at nucleotide position 1013, causing the arginine (R) at amino acid position 338 to be replaced by a glutamine (Q). 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

Benign

0.29

BayesDel_addAF

Uncertain

0.12

BayesDel_noAF

Pathogenic

0.16

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.060

T;T;.;.

Eigen

Uncertain

0.65

Eigen_PC

Pathogenic

0.70

FATHMM_MKL

Uncertain

0.93

LIST_S2

Pathogenic

1.0

D;D;D;D

M_CAP

Uncertain

0.13

MetaRNN

Uncertain

0.74

D;D;D;D

MetaSVM

Uncertain

0.059

MutationAssessor

Uncertain

2.7

M;.;.;.

PrimateAI

Uncertain

0.72

PROVEAN

Benign

-2.1

N;N;N;.

REVEL

Pathogenic

0.67

Sift

Benign

0.040

D;T;D;.

Sift4G

Benign

0.072

T;T;T;T

Polyphen

0.80

P;D;D;.

Vest4

0.80

MVP

0.94

MPC

0.17

ClinPred

0.30

GERP RS

5.7

Varity_R

0.29

gMVP

0.75

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over