chr13-49544736-C-T

Variant names:

• chr13-49544736-C-T
• rs869312819
• NM_018191.4:c.1172+1G>A

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_018191.4(RCBTB1):​c.1172+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: RCBTB1 NM_018191.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:2
• Conservation: PhyloP100: 7.57

Genes affected

RCBTB1 (HGNC:18243): (RCC1 and BTB domain containing protein 1) This gene encodes a protein with an N-terminal RCC1 domain and a C-terminal BTB (broad complex, tramtrack and bric-a-brac) domain. In rat, over-expression of this gene in vascular smooth muscle cells induced cellular hypertrophy. In rat, the C-terminus of RCBTB1 interacts with the angiotensin II receptor-1A. In humans, this gene maps to a region of chromosome 13q that is frequently deleted in B-cell chronic lymphocytic leukemia and other lymphoid malignancies. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Pathogenic. Variant got 12 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 13-49544736-C-T is Pathogenic according to our data. Variant chr13-49544736-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 224621.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr13-49544736-C-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RCBTB1	NM_018191.4	c.1172+1G>A		splice_donor_variant, intron_variant	Intron 10 of 12	ENST00000378302.7	NP_060661.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RCBTB1	ENST00000378302.7	c.1172+1G>A		splice_donor_variant, intron_variant	Intron 10 of 12	1	NM_018191.4	ENSP00000367552.2
RCBTB1	ENST00000258646.3	c.1172+1G>A		splice_donor_variant, intron_variant	Intron 8 of 10	2		ENSP00000258646.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, single submitter

Submissions by phenotype

Exudative retinopathy;C0339539:Familial exudative vitreoretinopathy Pathogenic:1

-

Laboratory of Human Molecular Genetics, Department of Medical Research, Taipei Veterans General Hospital

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: research

- -

not provided Pathogenic:1

Oct 08, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 10 of the RCBTB1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in RCBTB1 are known to be pathogenic (PMID: 31494449). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with RCBTB1-related conditions (PMID: 33104391). ClinVar contains an entry for this variant (Variation ID: 224621). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	31
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
GERP RS		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.99		Position offset: 1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs869312819; hg19: chr13-50118872;