4-169690528-A-C

Position:

• chr4-169690528-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001829.4(CLCN3):​c.607-2A>C variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,126 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 31)
• Consequence: CLCN3 NM_001829.4 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.01

Genes affected

CLCN3 (HGNC:2021): (chloride voltage-gated channel 3) This gene encodes a member of the voltage-gated chloride channel (ClC) family. The encoded protein is present in all cell types and localized in plasma membranes and in intracellular vesicles. It is a multi-pass membrane protein which contains a ClC domain and two additional C-terminal CBS (cystathionine beta-synthase) domains. The ClC domain catalyzes the selective flow of Cl- ions across cell membranes, and the CBS domain may have a regulatory function. This protein plays a role in both acidification and transmitter loading of GABAergic synaptic vesicles, and in smooth muscle cell activation and neointima formation. This protein is required for lysophosphatidic acid (LPA)-activated Cl- current activity and fibroblast-to-myofibroblast differentiation. The protein activity is regulated by Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) in glioma cells. Multiple alternatively spliced transcript variants encoding different isoforms have been identified. [provided by RefSeq, Aug 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.049654048 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CLCN3	NM_001829.4	c.607-2A>C		splice_acceptor_variant, intron_variant		ENST00000513761.6	NP_001820.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CLCN3	ENST00000513761.6	c.607-2A>C		splice_acceptor_variant, intron_variant		1	NM_001829.4	ENSP00000424603.1
CLCN3	ENST00000347613.9	c.607-2A>C		splice_acceptor_variant, intron_variant		1		ENSP00000261514.5
CLCN3	ENST00000360642.7	c.607-2A>C		splice_acceptor_variant, intron_variant		2		ENSP00000353857.3
CLCN3	ENST00000507875.6	c.526-2A>C		splice_acceptor_variant, intron_variant		2		ENSP00000425323.2

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152126 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.0000483

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: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 30

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152126 Hom.: 0 Cov.: 31 AF XY: 0.0000269 AC XY: 2 AN XY: 74314

Gnomad4 AFR AF: 0.0000483

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: 0.00

Gnomad4 OTH AF: 0.00

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 01, 2023

Loss of function has not been established as a mechanism of disease 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
BayesDel_addAF	Pathogenic	0.39	D
BayesDel_noAF	Pathogenic	0.32
CADD	Pathogenic	32
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
GERP RS		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.99		Position offset: 2

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

Publications

LitVar

Other links and lift over

dbSNP: rs1288867801; hg19: chr4-170611679;