rs376026619

chr7-143332829-C-Gchr7-143332829-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PM5 BP4

The NM_000083.3(CLCN1):c.1357C>G(p.Arg453Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,868 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/20 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R453W) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: CLCN1 NM_000083.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.318

Genes affected

CLCN1 (HGNC:2019): (chloride voltage-gated channel 1) The CLCN family of voltage-dependent chloride channel genes comprises nine members (CLCN1-7, Ka and Kb) which demonstrate quite diverse functional characteristics while sharing significant sequence homology. The protein encoded by this gene regulates the electric excitability of the skeletal muscle membrane. Mutations in this gene cause two forms of inherited human muscle disorders: recessive generalized myotonia congenita (Becker) and dominant myotonia (Thomsen). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Mar 2012]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-143332829-C-T is described in Lovd as [Pathogenic].
• BP4: Computational evidence support a benign effect (MetaRNN=0.27408317).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLCN1	NM_000083.3	c.1357C>G	p.Arg453Gly	missense_variant	12/23	ENST00000343257.7
CLCN1	NR_046453.2	n.1356+326C>G		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CLCN1	ENST00000343257.7	c.1357C>G	p.Arg453Gly	missense_variant	12/23	1	NM_000083.3	P4
CLCN1	ENST00000432192.6	c.*642C>G		3_prime_UTR_variant, NMD_transcript_variant	12/23	1
CLCN1	ENST00000650516.2	c.1357C>G	p.Arg453Gly	missense_variant	12/23			A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251452 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135896

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461868 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727244

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.079
BayesDel_addAF	Benign	-0.12	T
BayesDel_noAF	Benign	-0.33
Cadd	Benign	15
Dann	Uncertain	0.98
DEOGEN2	Uncertain	0.68	D
Eigen	Benign	-0.82
Eigen_PC	Benign	-0.77
FATHMM_MKL	Benign	0.30	N
LIST_S2	Uncertain	0.93	D
M_CAP	Uncertain	0.15	D
MetaRNN	Benign	0.27	T
MetaSVM	Benign	-0.75	T
MutationAssessor	Benign	0.070	N
MutationTaster	Benign	1.0	N
PrimateAI	Benign	0.20	T
PROVEAN	Uncertain	-2.8	D
REVEL	Benign	0.24
Sift	Benign	0.17	T
Sift4G	Benign	0.37	T
Polyphen		0.17	B
Vest4		0.41
MutPred		0.62		Loss of catalytic residue at R453 (P = 0.0367);
MVP		0.74
MPC		0.25
ClinPred		0.13	T
GERP RS		2.5
Varity_R		0.51
gMVP		0.56

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: rs376026619; hg19: chr7-143029922;