chr10-99818820-C-T
Variant summary
Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PP3_StrongPP5_Very_Strong
The NM_000392.5(ABCC2):c.2302C>T(p.Arg768Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000105 in 1,614,112 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R768Q) has been classified as Uncertain significance.
Frequency
Consequence
NM_000392.5 missense
Scores
Clinical Significance
Conservation
Publications
- Dubin-Johnson syndromeInheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Pathogenic. The variant received 12 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes  0.0000920  AC: 14AN: 152128Hom.:  0  Cov.: 32 show subpopulations 
GnomAD2 exomes  AF:  0.0000875  AC: 22AN: 251312 AF XY:  0.000118   show subpopulations 
GnomAD4 exome  AF:  0.000107  AC: 156AN: 1461868Hom.:  0  Cov.: 32 AF XY:  0.000114  AC XY: 83AN XY: 727230 show subpopulations 
Age Distribution
GnomAD4 genome  0.0000920  AC: 14AN: 152244Hom.:  0  Cov.: 32 AF XY:  0.0000806  AC XY: 6AN XY: 74424 show subpopulations 
Age Distribution
ClinVar
Submissions by phenotype
Dubin-Johnson syndrome    Pathogenic:5 
The p.Arg768Trp variant in ABCC2 has been reported in 3 homozygous individuals and 3 compound heterozygous individuals with Dubin-Johnson syndrome (DJS) and 1 compound heterozygous individual with intrahepatic cholestasis and segregated with disease in 2 affected individuals from 2 families (Wada 1998, Toh 1999, Materna 2003, Pacifico 2010, Okada 2014, Wang 2016). It has also been identified in 0.06% (12/19952) of East Asian chromosomes by gnomAD (http://gnomad.broadinstitute.org) and has been reported in ClinVar (Variation ID: 8412). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In vitro functional studies provide some evidence that this variant impacts protein function (Hashimoto 2002); however, these types of assays may not accurately represent biological function. In summary, although additional studies are required to fully establish its clinical significance, this variant meets criteria to be classified as likely pathogenic for autosomal recessive DJS. ACMG/AMP Criteria applied: PM3_Strong, PP1, PP3, PS3_Supporting. -
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The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.009%). Predicted Consequence/Location: The majority of the known disease-causing variants of this gene are variants expected to result in premature termination of the protein. In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.92 (>=0.6, sensitivity 0.68 and specificity 0.92)]. Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000008412 /PMID: 9425227). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -
Variant summary: ABCC2 c.2302C>T (p.Arg768Trp) results in a non-conservative amino acid change located in the ABC transporter-like, ATP-binding domain (IPR003439) 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 8.8e-05 in 251312 control chromosomes. c.2302C>T has been reported in the literature in multiple homozygous and compound heterozygous individuals affected with Dubin-Johnson Syndrome (e.g. Toh_1999). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 10053008). ClinVar contains an entry for this variant (Variation ID: 8412). Based on the evidence outlined above, the variant was classified as pathogenic. -
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not provided    Pathogenic:3 
ABCC2: PM3:Very Strong, PM2, PP3, PS3:Supporting -
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 768 of the ABCC2 protein (p.Arg768Trp). This variant is present in population databases (rs56199535, gnomAD 0.06%). This missense change has been observed in individuals with Dubin-Johnson syndrome (PMID: 9425227, 31544333). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 8412). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt ABCC2 protein function with a positive predictive value of 80%. For these reasons, this variant has been classified as Pathogenic. -
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ABCC2-related disorder    Pathogenic:1 
The ABCC2 c.2302C>T variant is predicted to result in the amino acid substitution p.Arg768Trp. This variant has been reported in the homozygous and compound heterozygous states to be causative for autosomal recessive Dubin-Johnson syndrome (Wada et al. 1998. PubMed ID: 9425227; Corpechot et al. 2019. PubMed ID: 31544333; Kim et al. 2020. PubMed ID: 32758197). This variant leads to deficient maturation and impaired sorting using in vitro functional assays (Hashimoto et al. 2002. PubMed ID: 12395335). This variant is reported in 0.060% of alleles in individuals of East Asian descent in gnomAD. This variant is interpreted as pathogenic. -
Computational scores
Source: 
Splicing
 Find out detailed SpliceAI scores and Pangolin per-transcript scores at