7-87444965-G-GA

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1PM2PP5

The NM_000443.4(ABCB4):​c.1015_1016insT​(p.Ser339PhefsTer17) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00119 in 1,553,300 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0013 ( 0 hom. )

Consequence

ABCB4
NM_000443.4 frameshift

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:1

Conservation

PhyloP100: 2.53
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]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 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 7-87444965-G-GA is Pathogenic according to our data. Variant chr7-87444965-G-GA is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 812984.We mark this variant Likely_pathogenic, oryginal submissions are: {Pathogenic=3, Uncertain_significance=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE UniProt
ABCB4NM_000443.4 linkuse as main transcriptc.1015_1016insT p.Ser339PhefsTer17 frameshift_variant 10/28 ENST00000649586.2

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Appris UniProt
ABCB4ENST00000649586.2 linkuse as main transcriptc.1015_1016insT p.Ser339PhefsTer17 frameshift_variant 10/28 NM_000443.4 P1P21439-2

Frequencies

GnomAD3 genomes
AF:
0.0000335
AC:
5
AN:
149280
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000246
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000666
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.000212
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000297
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00131
AC:
1838
AN:
1403916
Hom.:
0
Cov.:
30
AF XY:
0.00118
AC XY:
828
AN XY:
698796
show subpopulations
Gnomad4 AFR exome
AF:
0.00125
Gnomad4 AMR exome
AF:
0.000708
Gnomad4 ASJ exome
AF:
0.000921
Gnomad4 EAS exome
AF:
0.000447
Gnomad4 SAS exome
AF:
0.000796
Gnomad4 FIN exome
AF:
0.000890
Gnomad4 NFE exome
AF:
0.00144
Gnomad4 OTH exome
AF:
0.00107
GnomAD4 genome
AF:
0.0000335
AC:
5
AN:
149384
Hom.:
0
Cov.:
33
AF XY:
0.0000549
AC XY:
4
AN XY:
72804
show subpopulations
Gnomad4 AFR
AF:
0.0000245
Gnomad4 AMR
AF:
0.0000666
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.000212
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000297
Gnomad4 OTH
AF:
0.00

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:1Uncertain:1
Pathogenic, criteria provided, single submitterclinical testingInvitaeDec 30, 2023This sequence change creates a premature translational stop signal (p.Ser339Phefs*17) 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). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This premature translational stop signal has been observed in individual(s) with ABCB4-related conditions (PMID: 32581362, 32893960). ClinVar contains an entry for this variant (Variation ID: 812984). For these reasons, this variant has been classified as Pathogenic. -
Uncertain significance, criteria provided, single submitterclinical testingMayo Clinic Laboratories, Mayo ClinicSep 07, 2021- -
ABCB4-related disorder Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingPreventionGenetics, part of Exact SciencesFeb 12, 2024The ABCB4 c.1015dupT variant is predicted to result in a frameshift and premature protein termination (p.Ser339Phefs*17). This variant has been reported in the heterozygous state in multiple individuals with low phospholipid associated cholelithiasis (Rosmorduc et al. 2003. PubMed ID: 12891548; Poupon et al. 2013. PubMed ID: 23533021; Turro et al. 2020. PubMed ID: 32581362; Table S1, de Vries et al. 2020. PubMed ID: 32893960). This variant is reported in 0.17% of alleles in individuals of European (Finnish) descent in gnomAD; however, this variant failed to pass quality control filters in the gnomAD data. Frameshift variants in ABCB4 are expected to be pathogenic. Given the evidence, we interpret this variant as pathogenic. -
Cholestasis, intrahepatic, of pregnancy, 3 Pathogenic:1
Pathogenic, no assertion criteria providedresearchNIHR Bioresource Rare Diseases, University of Cambridge-- -
Progressive familial intrahepatic cholestasis type 3 Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingLaboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert EinsteinApr 20, 2022ACMG classification criteria: PVS1 very strong, PS4 moderated, PM2 moderated -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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: rs753104429; hg19: chr7-87074281; API