chr7-87447080-G-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1PM2PP2PP3PP5_Very_Strong

The NM_000443.4(ABCB4):​c.959C>T​(p.Ser320Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000174 in 1,613,618 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 Pathogenic (★★).

Frequency

Genomes: 𝑓 0.00017 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00017 ( 0 hom. )

Consequence

ABCB4
NM_000443.4 missense

Scores

9
9
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:13U:1

Conservation

PhyloP100: 3.28
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 14 ACMG points.

PM1
In a helix (size 52) in uniprot entity MDR3_HUMAN there are 6 pathogenic changes around while only 0 benign (100%) in NM_000443.4
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), ABCB4. . Gene score misZ 1.9749 (greater than the threshold 3.09). Trascript score misZ 3.5425 (greater than threshold 3.09). GenCC has associacion of gene with pancreatitis, low phospholipid associated cholelithiasis, progressive familial intrahepatic cholestasis type 3.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.795
PP5
Variant 7-87447080-G-A is Pathogenic according to our data. Variant chr7-87447080-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 13690.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-87447080-G-A is described in Lovd as [Pathogenic]. Variant chr7-87447080-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
ABCB4NM_000443.4 linkuse as main transcriptc.959C>T p.Ser320Phe missense_variant 9/28 ENST00000649586.2 NP_000434.1

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
ABCB4ENST00000649586.2 linkuse as main transcriptc.959C>T p.Ser320Phe missense_variant 9/28 NM_000443.4 ENSP00000496956 P1P21439-2

Frequencies

GnomAD3 genomes
AF:
0.000171
AC:
26
AN:
152152
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000131
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:
0.000309
Gnomad OTH
AF:
0.000478
GnomAD3 exomes
AF:
0.000155
AC:
39
AN:
251176
Hom.:
0
AF XY:
0.000162
AC XY:
22
AN XY:
135746
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.000174
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000291
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.000174
AC:
254
AN:
1461466
Hom.:
0
Cov.:
31
AF XY:
0.000164
AC XY:
119
AN XY:
727062
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.000134
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000348
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.000214
Gnomad4 OTH exome
AF:
0.000116
GnomAD4 genome
AF:
0.000171
AC:
26
AN:
152152
Hom.:
0
Cov.:
33
AF XY:
0.000229
AC XY:
17
AN XY:
74324
show subpopulations
Gnomad4 AFR
AF:
0.0000483
Gnomad4 AMR
AF:
0.000131
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.000309
Gnomad4 OTH
AF:
0.000478
Alfa
AF:
0.000232
Hom.:
0
Bravo
AF:
0.000155
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.000115
AC:
14
EpiCase
AF:
0.000164
EpiControl
AF:
0.000119

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:13Uncertain:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not provided Pathogenic:6
Pathogenic, criteria provided, single submitterclinical testingCeGaT Center for Human Genetics TuebingenJul 01, 2021- -
Likely pathogenic, no assertion criteria providedclinical testingClinical Genetics DNA and cytogenetics Diagnostics Lab, Erasmus MC, Erasmus Medical Center-- -
Pathogenic, criteria provided, single submitterclinical testingEurofins Ntd Llc (ga)Aug 24, 2018- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJan 30, 2024This sequence change replaces serine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 320 of the ABCB4 protein (p.Ser320Phe). This variant is present in population databases (rs72552778, gnomAD 0.03%). This missense change has been observed in individuals with clinical features of autosomal recessive progressive familial intrahepatic cholestasis type 3 (PMID: 11313316, 32893960). ClinVar contains an entry for this variant (Variation ID: 13690). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on ABCB4 protein function. Studies have shown that this missense change alters ABCB4 gene expression (PMID: 24806754). For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitterclinical testingGeneDxOct 15, 2024One in vitro study showed decreased transport activity, while another showed reduced protein expression but normal protein function (PMID: 26153658, 24381502); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 19490418, 17562004, 26699824, 23533021, 24381502, 22331132, 11313316, 19840255, 17786139, 19584064, 15077010, 16890614, 17726488, 21119540, 26324191, 28776642, 29761167, 24806754, 28733223, 30487145, 31538484, 32793533, 32581362, 35288833, 37822304, 34376370, 33258288, 36330364, 33390354, 32893960, 32650689, 26153658) -
Pathogenic, no assertion criteria providedclinical testingGenome Diagnostics Laboratory, University Medical Center Utrecht-- -
Low phospholipid associated cholelithiasis Pathogenic:3
Pathogenic, no assertion criteria providedliterature onlyOMIMOct 01, 2009- -
Pathogenic, criteria provided, single submitterclinical testingIllumina Laboratory Services, IlluminaApr 28, 2017Across a selection of the available literature, the ABCB4 c.959C>T (p.Ser320Phe) missense variant has been identified in a homozygous state in four patients with intrahepatic cholestasis of pregnancy, in a homozygous state in one patient with progressive familial intrahepatic cholestasis type 3, in a homozygous state in one patient with low phospholipid associated cholelithiasis, and in a compound heterozygotes state in seven patients with progressive familial intrahepatic cholestasis type 3 (Rosmorduc et al. 2001; Rosmorduc et al. 2003; Pauli-Magnus et al. 2004; Keitel et al. 2006; Degiorgio et al. 2007; Colombo et al. 2011; Oliveira et al. 2016). The p.Ser320Phe variant was absent from 630 controls and is reported at a frequency of 0.00020 in the European (non-Finnish) population of the Exome Aggregation Consortium. Transfection of the p.Ser320Phe variant into HEK293T and MDCK-II cells showed that the variant protein had similar activity as compared to wild type, however the expression levels were slightly reduced (Kim et al. 2013; Andress et al. 2014; Gordo-Gilart et al. 2016). Based on the evidence, the p.Ser320Phe variant is classified as pathogenic for ABCB4-related intrahepatic cholestasis. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
Pathogenic, criteria provided, single submitterclinical testingMendelicsMay 04, 2022- -
Cholestasis, intrahepatic, of pregnancy, 3 Pathogenic:2
Pathogenic, no assertion criteria providedliterature onlyOMIMOct 01, 2009- -
Pathogenic, no assertion criteria providedresearchNIHR Bioresource Rare Diseases, University of Cambridge-- -
ABCB4-related disorder Pathogenic:1
Likely pathogenic, no assertion criteria providedclinical testingPreventionGenetics, part of Exact SciencesMar 05, 2024The ABCB4 c.959C>T variant is predicted to result in the amino acid substitution p.Ser320Phe. This variant has been reported in the homozygous or compound heterozygous state in several individuals with cholestasis phenotypes (see for example, Rosmorduc et al. 2001. PubMed ID: 11313316; Keitel et al. 2006. PubMed ID: 16890614; Degiorgio et al. 2007 PubMed ID: 17726488). In vitro functional assessment has been inconclusive (Kim et al. 2013. PubMed ID: 24381502; Andress et al. 2014. PubMed ID: 24806754; Gordo-Gilart et al. 2015. PubMed ID: 26153658). This variant is reported in 0.029% of alleles in individuals of European (Non-Finnish) descent in gnomAD. This variant is interpreted as likely pathogenic. -
Progressive familial intrahepatic cholestasis Pathogenic:1
Pathogenic, criteria provided, single submitterclinical testingWomen's Health and Genetics/Laboratory Corporation of America, LabCorpMar 02, 2023Variant summary: ABCB4 c.959C>T (p.Ser320Phe) results in a non-conservative amino acid change located in the ABC transporter type 1, transmembrane domain (IPR011527) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 0.00016 in 251176 control chromosomes (gnomAD). This frequency is not significantly higher than estimated for a pathogenic variant in ABCB4 causing Familial Intrahepatic Cholestasis (0.00016 vs 0.0022), allowing no conclusion about variant significance. c.959C>T has been reported in the literature in multiple individuals affected with Familial Intrahepatic Cholestasis (example: Rosmmorduc_2001 and de Vries_2020). These data indicate that the variant is very likely to be associated with disease. Six clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and all classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Progressive familial intrahepatic cholestasis type 3 Uncertain:1
Uncertain significance, flagged submissionclinical testingLaboratory for Molecular Medicine, Mass General Brigham Personalized MedicineAug 22, 2014The Ser320Phe variant in ABCB4 has been reported in 9 heterozygous, 6 homozygous, and 4 compound heterozygous individuals with cholestatic liver disease (Andress 2014, Poupon 2013, Wendum 2012, Bacq 2009, Degiorgio 2007, Colombo 2011, Rosmorduc 2001, Pauli-Magnus 2004, Zimmer 2009, Keitel 2006). This variant has been identified in 1/8600 of European American chromosomes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/; dbSNP rs72552778). Computational analyses (biochemical amino acid properties, conservation and PolyPhen2) do not provide strong support for or against an impact to the protein. In vitro assays suggest the Ser320Phe variant may affect protein function (Andress 2014, Kim 2013); however these types of assays may not accurately represent biological function. In summary, while there is some suspicion for a pathogenic role, the clinical significance of the Ser320Phe variant is uncertain. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.69
BayesDel_addAF
Pathogenic
0.20
D
BayesDel_noAF
Pathogenic
0.36
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.74
.;.;D;.;.
Eigen
Pathogenic
0.74
Eigen_PC
Pathogenic
0.73
FATHMM_MKL
Uncertain
0.93
D
LIST_S2
Uncertain
0.97
.;D;D;D;.
M_CAP
Pathogenic
0.58
D
MetaRNN
Pathogenic
0.80
D;D;D;D;D
MetaSVM
Pathogenic
0.85
D
MutationAssessor
Uncertain
2.5
M;M;M;M;M
MutationTaster
Benign
1.0
A;A;A;A;A
PrimateAI
Uncertain
0.58
T
PROVEAN
Uncertain
-3.7
.;D;D;D;D
REVEL
Pathogenic
0.83
Sift
Uncertain
0.0010
.;D;D;D;D
Sift4G
Uncertain
0.0060
.;D;D;D;D
Polyphen
0.95
P;.;P;P;.
Vest4
0.83, 0.82, 0.84, 0.84
MVP
0.95
MPC
0.93
ClinPred
0.35
T
GERP RS
5.7
Varity_R
0.88
gMVP
0.97

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.010
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: rs72552778; hg19: chr7-87076396; API