NM_000083.3:c.1655A>T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PM2PM5PP2PP3_Strong

The NM_000083.3(CLCN1):c.1655A>T(p.Gln552Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,886 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. Q552R) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 9.32

Publications

9 publications found

Variant links:

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]

CLCN1 Gene-Disease associations (from GenCC):

myotonia congenita, autosomal dominant
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
myotonia congenita, autosomal recessive
Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
Thomsen and Becker disease
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

CLCN1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 11 ACMG points.

PM1

In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000083.3

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr7-143342001-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 17538.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 106 curated pathogenic missense variants (we use a threshold of 10). The gene has 18 curated benign missense variants. Gene score misZ: 0.21191 (below the threshold of 3.09). Trascript score misZ: 0.95247 (below the threshold of 3.09). GenCC associations: The gene is linked to myotonia congenita, autosomal dominant, myotonia congenita, autosomal recessive, Thomsen and Becker disease.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.954

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CLCN1	NM_000083.3 link	c.1655A>T	p.Gln552Leu	missense_variant	Exon 15 of 23	ENST00000343257.7	NP_000074.3	P35523
CLCN1	NR_046453.2 link	n.1610A>T		non_coding_transcript_exon_variant	Exon 14 of 22

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
CLCN1	ENST00000343257.7 link	c.1655A>T	p.Gln552Leu	missense_variant	Exon 15 of 23	1	NM_000083.3	ENSP00000339867.2	P35523
CLCN1	ENST00000432192.6 link	n.*940A>T		non_coding_transcript_exon_variant	Exon 15 of 23	1		ENSP00000395949.2	H7C0N6
CLCN1	ENST00000432192.6 link	n.*940A>T		3_prime_UTR_variant	Exon 15 of 23	1		ENSP00000395949.2	H7C0N6
CLCN1	ENST00000650516.2 link	c.1655A>T	p.Gln552Leu	missense_variant	Exon 15 of 23			ENSP00000498052.2	A0A3B3IU72

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251238

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000462

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461886

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727244

show subpopulations

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.0000187

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5764

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1112012

Other (OTH)

AF:

0.00

AC:

AN:

60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.225

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ExAC

AF:

0.00000824

AC:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.32

BayesDel_noAF

Pathogenic

0.22

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.86

Eigen

Pathogenic

0.87

Eigen_PC

Pathogenic

0.80

FATHMM_MKL

Pathogenic

0.98

LIST_S2

Pathogenic

0.98

M_CAP

Pathogenic

0.77

MetaRNN

Pathogenic

0.95

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

3.8

PhyloP100

9.3

PrimateAI

Uncertain

0.77

PROVEAN

Pathogenic

-6.3

REVEL

Pathogenic

0.88

Sift

Uncertain

0.0010

Sift4G

Pathogenic

0.0010

Polyphen

1.0

Vest4

0.90

MutPred

0.71

Gain of helix (P = 0.0425);

MVP

0.98

MPC

0.73

ClinPred

1.0

GERP RS

4.8

Varity_R

0.94

gMVP

0.92

Mutation Taster

=48/52

disease causing

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over