chr7-87443683-G-A

Variant names:

• chr7-87443683-G-A
• rs863225298
• NM_000443.4:c.1210C>T

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_000443.4(ABCB4):​c.1210C>T​(p.Pro404Ser) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. P404A) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ABCB4 NM_000443.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.84
• Publications: 0 publications found

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]

ABCB4 Gene-Disease associations (from GenCC):

• progressive familial intrahepatic cholestasis type 3

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, Orphanet
• gallbladder disease 1

  Inheritance: SD, AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet
• pancreatitis

  Inheritance: AD Classification: LIMITED Submitted by: Ambry Genetics

ACMG classification

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_000443.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-87443683-G-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 242455.
• PP2: Missense variant in the ABCB4 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 32 curated pathogenic missense variants (we use a threshold of 10). The gene has 6 curated benign missense variants. Gene score misZ: 1.9749 (below the threshold of 3.09). Trascript score misZ: 3.5425 (above the threshold of 3.09). GenCC associations: The gene is linked to gallbladder disease 1, progressive familial intrahepatic cholestasis type 3, pancreatitis.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.957

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ABCB4	NM_000443.4	c.1210C>T	p.Pro404Ser	missense_variant	Exon 11 of 28	ENST00000649586.2	NP_000434.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABCB4	ENST00000649586.2	c.1210C>T	p.Pro404Ser	missense_variant	Exon 11 of 28		NM_000443.4	ENSP00000496956.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Progressive familial intrahepatic cholestasis type 3 Uncertain:1

May 22, 2022

3billion

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. In silico tool predictions suggest damaging effect of the variant on gene or gene product (REVEL: 0.81; 3Cnet: 0.53). A different missense change at the same codon (p.Pro404Ala) has been reported to be associated with ABCB4 related disorder (ClinVar ID: VCV000242455 / PMID: 31538484). Therefore, this variant is classified as uncertain significanceaccording to the recommendation of ACMG/AMP guideline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.64
BayesDel_addAF	Pathogenic	0.24	D
BayesDel_noAF	Uncertain	0.11
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.85	.;.;D;.;.
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.60
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Pathogenic	0.98	.;D;D;D;.
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D
MetaSVM	Uncertain	0.62	D
MutationAssessor	Benign	1.4	L;L;L;L;L
PhyloP100		6.8
PrimateAI	Uncertain	0.53	T
PROVEAN	Pathogenic	-7.0	.;D;D;D;D
REVEL	Pathogenic	0.81
Sift	Pathogenic	0.0	.;D;D;D;D
Sift4G	Uncertain	0.0030	.;D;D;D;D
Polyphen		1.0	D;.;D;D;.
Vest4		0.72, 0.60, 0.63, 0.71
MutPred		0.83		Gain of MoRF binding (P = 0.0544);Gain of MoRF binding (P = 0.0544);Gain of MoRF binding (P = 0.0544);Gain of MoRF binding (P = 0.0544);Gain of MoRF binding (P = 0.0544);
MVP		0.88
MPC		0.86
ClinPred		1.0	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.1
Varity_R		0.87
gMVP		0.91
Mutation Taster		=6/94	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs863225298; hg19: chr7-87072999;