4-169687707-A-G

Position:

• chr4-169687707-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_001829.4(CLCN3):​c.368A>G​(p.Tyr123Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,458,312 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: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: CLCN3 NM_001829.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 4.22

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.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), CLCN3. . Gene score misZ 4.3745 (greater than the threshold 3.09). Trascript score misZ 5.1954 (greater than threshold 3.09). GenCC has associacion of gene with neurodevelopmental disorder with seizures and brain abnormalities, complex neurodevelopmental disorder, neurodevelopmental disorder with hypotonia and brain abnormalities.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.795

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
CLCN3	NM_001829.4	c.368A>G	p.Tyr123Cys	missense_variant	4/13	ENST00000513761.6	NP_001820.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
CLCN3	ENST00000513761.6	c.368A>G	p.Tyr123Cys	missense_variant	4/13	1	NM_001829.4	ENSP00000424603.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458312 Hom.: 0 Cov.: 28 AF XY: 0.00000276 AC XY: 2 AN XY: 725388

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: 0.0000117

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.01e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000756

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

May 20, 2024

The c.368A>G (p.Y123C) alteration is located in exon 1 (coding exon 1) of the CLCN3 gene. This alteration results from a A to G substitution at nucleotide position 368, causing the tyrosine (Y) at amino acid position 123 to be replaced by a cysteine (C). 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	0.14
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Benign	23
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.76	.;D;.;.;T;.;.;.
Eigen	Uncertain	0.38
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.88	D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.79	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.49	D
MutationAssessor	Uncertain	2.6	.;M;M;M;.;.;.;.
PrimateAI	Pathogenic	0.85	D
PROVEAN	Uncertain	-3.4	D;D;D;D;D;D;.;D
REVEL	Pathogenic	0.82
Sift	Benign	0.18	T;T;T;T;T;T;.;T
Sift4G	Benign	0.18	T;T;T;T;T;T;T;T
Polyphen		0.89, 0.93	.;P;P;.;.;P;.;.
Vest4		0.45, 0.46, 0.43, 0.45, 0.46
MutPred		0.60		Loss of helix (P = 0.0196);Loss of helix (P = 0.0196);Loss of helix (P = 0.0196);Loss of helix (P = 0.0196);Loss of helix (P = 0.0196);.;.;.;
MVP		0.94
MPC		2.3
ClinPred		0.98	D
GERP RS		4.1
Varity_R		0.20
gMVP		0.98

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: rs1581251098; hg19: chr4-170608858;