rs8187801

Positions:

• chr7-87420029-C-A
• chr7-87420029-C-G
• chr7-87420029-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_000443.4(ABCB4):​c.2363G>T​(p.Arg788Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000752 in 1,461,806 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R788Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: ABCB4 NM_000443.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.85

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a domain ABC transmembrane type-1 2 (size 288) in uniprot entity MDR3_HUMAN there are 25 pathogenic changes around while only 2 benign (93%) in NM_000443.4
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, ABCB4
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.964

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABCB4	NM_000443.4	c.2363G>T	p.Arg788Leu	missense_variant	19/28	ENST00000649586.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABCB4	ENST00000649586.2	c.2363G>T	p.Arg788Leu	missense_variant	19/28		NM_000443.4	P1
ABCB4	ENST00000265723.8	c.2363G>T	p.Arg788Leu	missense_variant	19/28	1
ABCB4	ENST00000359206.8	c.2363G>T	p.Arg788Leu	missense_variant	19/28	1		P1
ABCB4	ENST00000453593.5	c.2363G>T	p.Arg788Leu	missense_variant	18/26	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251236 Hom.: 0 AF XY: 0.0000147 AC XY: 2 AN XY: 135776

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.0000327

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461806 Hom.: 0 Cov.: 31 AF XY: 0.0000124 AC XY: 9 AN XY: 727212

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: 0.000104

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.92
BayesDel_addAF	Pathogenic	0.35	D
BayesDel_noAF	Pathogenic	0.36
CADD	Uncertain	24
DANN	Uncertain	1.0
Eigen	Uncertain	0.44
Eigen_PC	Uncertain	0.23
FATHMM_MKL	Uncertain	0.90	D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Pathogenic	4.3	H;H;H;H;H
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.52	T
Polyphen		1.0	D;.;D;D;.
Vest4		0.85, 0.89, 0.89, 0.84
MutPred		0.79		Loss of MoRF binding (P = 0.0226);Loss of MoRF binding (P = 0.0226);Loss of MoRF binding (P = 0.0226);Loss of MoRF binding (P = 0.0226);Loss of MoRF binding (P = 0.0226);
MVP		0.92
MPC		1.1
ClinPred		1.0	D
GERP RS		4.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.97
gMVP		0.97

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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

Other links and lift over

dbSNP: rs8187801; hg19: chr7-87049345;