chr7-87402260-A-C

Position:

• chr7-87402260-A-C

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.3676T>G​(p.Cys1226Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000539 in 1,613,980 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 Uncertain significance (★★).

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000057 (0 hom.)
• Consequence: ABCB4 NM_000443.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 9.32

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 transporter 2 (size 245) in uniprot entity MDR3_HUMAN there are 10 pathogenic changes around while only 2 benign (83%) 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, 0.963

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
ABCB4	NM_000443.4	c.3676T>G	p.Cys1226Gly	missense_variant	28/28	ENST00000649586.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
ABCB4	ENST00000649586.2	c.3676T>G	p.Cys1226Gly	missense_variant	28/28		NM_000443.4	P1

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152234 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

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: 0.0000441

Gnomad OTH AF: 0.000478

GnomAD3 exomes AF: 0.0000279 AC: 7 AN: 251138 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135738

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: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000617

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000568 AC: 83 AN: 1461746 Hom.: 0 Cov.: 30 AF XY: 0.0000646 AC XY: 47 AN XY: 727186

Gnomad4 AFR exome AF: 0.0000299

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: 0.0000710

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152234 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74374

Gnomad4 AFR AF: 0.00

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: 0.0000441

Gnomad4 OTH AF: 0.000478

Alfa AF: 0.000154 Hom.: 0

Bravo AF: 0.0000491

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Feb 03, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Jan 17, 2017	- -

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 18, 2021

The c.3676T>G (p.C1226G) alteration is located in exon 28 (coding exon 27) of the ABCB4 gene. This alteration results from a T to G substitution at nucleotide position 3676, causing the cysteine (C) at amino acid position 1226 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.33
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	28
DANN	Uncertain	0.98
Eigen	Uncertain	0.42
Eigen_PC	Uncertain	0.53
FATHMM_MKL	Pathogenic	0.99	D
M_CAP	Uncertain	0.27	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D
MetaSVM	Benign	-0.81	T
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.70	T
Polyphen		1.0	D;.;D;D;.
Vest4		0.83, 0.77, 0.83
MVP		0.90
MPC		0.46
ClinPred		0.83	D
GERP RS		5.5
Varity_R		0.96
gMVP		0.84

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

Other links and lift over

dbSNP: rs769306313; hg19: chr7-87031576;