rs121918440

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000443.4(ABCB4):​c.2869C>T​(p.Arg957Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,613,706 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

ABCB4
NM_000443.4 stop_gained

Scores

2
4
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 2.27
Variant links:
Genes affected
ABCB4 (HGNC:45): (ATP binding cassette subfamily B member 4) The membrane-associated protein encoded by this gene is a member of the superfamily of ATP-binding cassette (ABC) transporters. ABC proteins transport various molecules across extra- and intra-cellular membranes. ABC genes are divided into seven distinct subfamilies (ABC1, MDR/TAP, MRP, ALD, OABP, GCN20, White). This protein is a member of the MDR/TAP subfamily. Members of the MDR/TAP subfamily are involved in multidrug resistance as well as antigen presentation. This gene encodes a full transporter and member of the p-glycoprotein family of membrane proteins with phosphatidylcholine as its substrate. The function of this protein has not yet been determined; however, it may involve transport of phospholipids from liver hepatocytes into bile. Alternative splicing of this gene results in several products of undetermined function. [provided by RefSeq, Jul 2008]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 18 ACMG points.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 7-87411948-G-A is Pathogenic according to our data. Variant chr7-87411948-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 13687.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-87411948-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
ABCB4NM_000443.4 linkuse as main transcriptc.2869C>T p.Arg957Ter stop_gained 23/28 ENST00000649586.2 NP_000434.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
ABCB4ENST00000649586.2 linkuse as main transcriptc.2869C>T p.Arg957Ter stop_gained 23/28 NM_000443.4 ENSP00000496956 P1P21439-2
ABCB4ENST00000265723.8 linkuse as main transcriptc.2869C>T p.Arg957Ter stop_gained 23/281 ENSP00000265723 P21439-1
ABCB4ENST00000359206.8 linkuse as main transcriptc.2869C>T p.Arg957Ter stop_gained 23/281 ENSP00000352135 P1P21439-2
ABCB4ENST00000453593.5 linkuse as main transcriptc.2783+1669C>T intron_variant 5 ENSP00000392983 P21439-3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152140
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000724
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
GnomAD4 exome
AF:
0.00000205
AC:
3
AN:
1461566
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
727076
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.0000166
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152140
Hom.:
0
Cov.:
33
AF XY:
0.0000269
AC XY:
2
AN XY:
74322
show subpopulations
Gnomad4 AFR
AF:
0.0000724
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:
0.00
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000324
Hom.:
0
Bravo
AF:
0.0000151

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:5
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Pathogenic, criteria provided, single submitterclinical testingRevvity Omics, RevvityFeb 03, 2020- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJun 25, 2023For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 13687). This premature translational stop signal has been observed in individual(s) with familial intrahepatic cholestasis (PMID: 9419367). This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Arg957*) in the ABCB4 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in ABCB4 are known to be pathogenic (PMID: 17726488, 25755532). -
Cholestasis, intrahepatic, of pregnancy, 3 Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMOct 18, 2017- -
Low phospholipid associated cholelithiasis Pathogenic:1
Likely pathogenic, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaDec 13, 2018The ABCB4 c.2869C>T (p.Arg957Ter) variant is a stop-gained variant that is predicted to result in a premature termination of the protein. The p.Arg957Ter variant has been reported in two studies and is found in two probands with progressive familial intrahepatic cholestasis, including one in a homozygous state and one in a compound heterozygous state (de Vree et al. 1998; Stalke et al. 2017). Canalicular staining for ABCB4 protein was negative in liver tissue of the homozygous proband, and Northern blot and Western blot analysis showed low level or absence of RNA and protein (de Vree et al. 1998). The homozygous proband was from a consanguineous family and no other probands with liver disease were reported in this family, except for the mother who had experienced episodes of cholestasis during pregnancy (de Vree et al. 1998). Control data are unavailable for this variant and it is not found in the 1000 Genomes Project, the Exome Sequencing Project, the Exome Aggregation Consortium, or the Genome Aggregation Database. Based on the evidence and potential impact of stop-gained variants, this variant is classified as likely pathogenic for ABCB4-related intrahepatic cholestasis. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Progressive familial intrahepatic cholestasis type 3 Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMOct 18, 2017- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.58
CADD
Pathogenic
41
DANN
Uncertain
1.0
Eigen
Uncertain
0.65
Eigen_PC
Uncertain
0.50
FATHMM_MKL
Uncertain
0.87
D
MutationTaster
Benign
1.0
A;A;A;A;A
Vest4
0.90
GERP RS
3.7

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.

Other links and lift over

dbSNP: rs121918440; hg19: chr7-87041264; COSMIC: COSV55934187; COSMIC: COSV55934187; API