12-21842440-C-G

Variant names:

• chr12-21842440-C-G
• rs387907227
• NM_020297.4:c.3347G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_020297.4(ABCC9):​c.3347G>C​(p.Arg1116Pro) variant causes a missense change involving the alteration of a conserved nucleotide. 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. R1116C) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: ABCC9 NM_020297.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.87
• Publications: 0 publications found

Genes affected

ABCC9 (HGNC:60): (ATP binding cassette subfamily C member 9) The 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 MRP subfamily which is involved in multi-drug resistance. This protein is thought to form ATP-sensitive potassium channels in cardiac, skeletal, and vascular and non-vascular smooth muscle. Protein structure suggests a role as the drug-binding channel-modulating subunit of the extra-pancreatic ATP-sensitive potassium channels. Mutations in this gene are associated with cardiomyopathy dilated type 1O. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Apr 2011]

ABCC9 Gene-Disease associations (from GenCC):

• hypertrichotic osteochondrodysplasia Cantu type

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, G2P, Labcorp Genetics (formerly Invitae), Ambry Genetics
• dilated cardiomyopathy 1O

  Inheritance: AD Classification: STRONG, MODERATE, LIMITED Submitted by: Illumina, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• intellectual disability and myopathy syndrome

  Inheritance: AR Classification: MODERATE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae)
• acromegaloid facial appearance syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• hypertrichosis-acromegaloid facial appearance syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Brugada syndrome

  Inheritance: AD Classification: LIMITED Submitted by: Genomics England PanelApp
• dilated cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen
• atrial fibrillation, familial, 12

  Inheritance: Unknown Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae)

ENSG00000257022 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-21842441-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 35534.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.907

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
ABCC9	NM_020297.4	c.3347G>C	p.Arg1116Pro	missense_variant	Exon 29 of 40	ENST00000261200.9	NP_064693.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
ABCC9	ENST00000261200.9	c.3347G>C	p.Arg1116Pro	missense_variant	Exon 29 of 40	5	NM_020297.4	ENSP00000261200.4

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

Dilated cardiomyopathy 1O Uncertain:1

Dec 21, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 1116 of the ABCC9 protein (p.Arg1116Pro). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with ABCC9-related conditions. 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) performed at Invitae indicates that this missense variant is expected to disrupt ABCC9 protein function with a positive predictive value of 80%. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. This variant disrupts the p.Arg1116 amino acid residue in ABCC9. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 22610116, 23307537, 25590979, 27316244). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.37
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.77	.;.;D
Eigen	Pathogenic	0.73
Eigen_PC	Pathogenic	0.70
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Uncertain	0.29	D
MetaRNN	Pathogenic	0.91	D;D;D
MetaSVM	Uncertain	0.72	D
MutationAssessor	Uncertain	2.9	M;.;M
PhyloP100		7.9
PrimateAI	Pathogenic	0.82	D
PROVEAN	Uncertain	-4.0	D;D;D
REVEL	Pathogenic	0.86
Sift	Benign	0.041	D;D;D
Sift4G	Uncertain	0.047	D;T;D
Polyphen		0.99	D;.;D
Vest4		0.86
MutPred		0.74		Gain of glycosylation at R1116 (P = 0.0551);.;Gain of glycosylation at R1116 (P = 0.0551);
MVP		0.97
MPC		1.9
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.98
gMVP		0.99
Mutation Taster		=8/92	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.12		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: rs387907227; hg19: chr12-21995374;