dbSNP rs147493705: CLCN1:p.Phe494Leu (chr7-143339519-T-C) – ACMG Classification: Likely_benign (-6 pts)

Variant summary

Our verdict is Likely benign. The variant received -6 ACMG points: 3P and 9B. PM1PP2BP4_StrongBP6BS2

The NM_000083.3(CLCN1):c.1480T>C(p.Phe494Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000242 in 1,612,644 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. F494F) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0013 ( 2 hom., cov: 32)

Exomes 𝑓: 0.00014 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1B:2O:1

Conservation

PhyloP100: 8.01

Publications

1 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: Likely_benign. The variant received -6 ACMG points.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000083.3

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.

BP4

Computational evidence support a benign effect (MetaRNN=0.044286817).

BP6

Variant 7-143339519-T-C is Benign according to our data. Variant chr7-143339519-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 418134.

BS2

High Homozygotes in GnomAd4 at 2 AD,AR gene

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000083.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CLCN1	NM_000083.3	MANE Select	c.1480T>C	p.Phe494Leu	missense	Exon 14 of 23	NP_000074.3	P35523
	CLCN1	NR_046453.2		n.1435T>C		non_coding_transcript_exon	Exon 13 of 22

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CLCN1	ENST00000343257.7	TSL:1 MANE Select	c.1480T>C	p.Phe494Leu	missense	Exon 14 of 23	ENSP00000339867.2	P35523
CLCN1	ENST00000432192.6	TSL:1	n.*765T>C		non_coding_transcript_exon	Exon 14 of 23	ENSP00000395949.2	H7C0N6
CLCN1	ENST00000432192.6	TSL:1	n.*765T>C		3_prime_UTR	Exon 14 of 23	ENSP00000395949.2	H7C0N6

Frequencies

GnomAD3 genomes

AF:

0.00122

AC:

185

AN:

152170

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00417

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000590

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:

0.00144

GnomAD2 exomes

AF:

0.000342

AC:

AN:

251454

AF XY:

0.000287

show subpopulations

Gnomad AFR exome

AF:

0.00406

Gnomad AMR exome

AF:

0.000549

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.000136

AC:

198

AN:

1460356

Hom.:

Cov.:

AF XY:

0.000113

AC XY:

AN XY:

726588

show subpopulations

African (AFR)

AF:

0.00457

AC:

153

AN:

33446

American (AMR)

AF:

0.000470

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86226

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.000347

AC:

AN:

5760

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1110622

Other (OTH)

AF:

0.000365

AC:

AN:

60336

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.468

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

AF:

0.00126

AC:

192

AN:

152288

Hom.:

Cov.:

AF XY:

0.00133

AC XY:

AN XY:

74464

show subpopulations

African (AFR)

AF:

0.00433

AC:

180

AN:

41572

American (AMR)

AF:

0.000589

AC:

AN:

15286

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68028

Other (OTH)

AF:

0.00142

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.494

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome 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

Alfa

AF:

0.000501

Hom.:

Bravo

AF:

0.00141

ESP6500AA

AF:

0.00272

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000354

AC:

Asia WGS

AF:

0.000289

AC:

AN:

3478

ClinVar

ClinVar submissions

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form (2)

not provided (1)

not specified (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.88

BayesDel_addAF

Benign

-0.20

BayesDel_noAF

Uncertain

-0.070

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Uncertain

0.77

Eigen

Benign

0.061

Eigen_PC

Uncertain

0.24

FATHMM_MKL

Uncertain

0.89

LIST_S2

Uncertain

0.93

M_CAP

Uncertain

0.17

MetaRNN

Benign

0.044

MetaSVM

Uncertain

-0.0019

MutationAssessor

Benign

1.5

PhyloP100

8.0

PrimateAI

Pathogenic

0.85

PROVEAN

Uncertain

-4.3

REVEL

Uncertain

0.49

Sift

Benign

0.13

Sift4G

Benign

0.10

Polyphen

0.052

Vest4

0.93

MutPred

0.49

Loss of catalytic residue at F494 (P = 0.0269)

MVP

0.94

MPC

0.40

ClinPred

0.10

GERP RS

5.1

Varity_R

0.71

gMVP

0.86

Mutation Taster

=72/28

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over