rs78085922

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_StrongBP6_Very_StrongBS1BS2

The NM_000083.3(CLCN1):​c.2244G>A​(p.Leu748Leu) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0134 in 1,613,444 control chromosomes in the GnomAD database, including 218 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★). Synonymous variant affecting the same amino acid position (i.e. L748L) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.017 ( 43 hom., cov: 31)
Exomes 𝑓: 0.013 ( 175 hom. )

Consequence

CLCN1
NM_000083.3 synonymous

Scores

2

Clinical Significance

Benign criteria provided, multiple submitters, no conflicts B:7

Conservation

PhyloP100: 1.89

Publications

2 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Benign. The variant received -20 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.49).
BP6
Variant 7-143346211-G-A is Benign according to our data. Variant chr7-143346211-G-A is described in ClinVar as Benign. ClinVar VariationId is 359122.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BS1
Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.0171 (2608/152086) while in subpopulation AFR AF = 0.0306 (1269/41460). AF 95% confidence interval is 0.0292. There are 43 homozygotes in GnomAd4. There are 1215 alleles in the male GnomAd4 subpopulation. Median coverage is 31. This position passed quality control check.
BS2
High Homozygotes in GnomAd4 at 43 AD,AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
CLCN1NM_000083.3 linkc.2244G>A p.Leu748Leu synonymous_variant Exon 18 of 23 ENST00000343257.7 NP_000074.3
CLCN1NR_046453.2 linkn.2199G>A non_coding_transcript_exon_variant Exon 17 of 22

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkc.2244G>A p.Leu748Leu synonymous_variant Exon 18 of 23 1 NM_000083.3 ENSP00000339867.2
CLCN1ENST00000432192.6 linkn.*1529G>A non_coding_transcript_exon_variant Exon 18 of 23 1 ENSP00000395949.2
CLCN1ENST00000432192.6 linkn.*1529G>A 3_prime_UTR_variant Exon 18 of 23 1 ENSP00000395949.2
CLCN1ENST00000650516.2 linkc.2244G>A p.Leu748Leu synonymous_variant Exon 18 of 23 ENSP00000498052.2

Frequencies

GnomAD3 genomes
AF:
0.0172
AC:
2607
AN:
151968
Hom.:
43
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.0306
Gnomad AMI
AF:
0.00877
Gnomad AMR
AF:
0.0134
Gnomad ASJ
AF:
0.0554
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00580
Gnomad FIN
AF:
0.00444
Gnomad MID
AF:
0.0191
Gnomad NFE
AF:
0.0120
Gnomad OTH
AF:
0.0182
GnomAD2 exomes
AF:
0.0130
AC:
3258
AN:
251308
AF XY:
0.0127
show subpopulations
Gnomad AFR exome
AF:
0.0308
Gnomad AMR exome
AF:
0.00888
Gnomad ASJ exome
AF:
0.0524
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00463
Gnomad NFE exome
AF:
0.0133
Gnomad OTH exome
AF:
0.0191
GnomAD4 exome
AF:
0.0131
AC:
19081
AN:
1461358
Hom.:
175
Cov.:
33
AF XY:
0.0128
AC XY:
9338
AN XY:
727014
show subpopulations
African (AFR)
AF:
0.0325
AC:
1089
AN:
33466
American (AMR)
AF:
0.00993
AC:
444
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0500
AC:
1307
AN:
26122
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.00678
AC:
585
AN:
86254
European-Finnish (FIN)
AF:
0.00465
AC:
248
AN:
53378
Middle Eastern (MID)
AF:
0.0106
AC:
61
AN:
5766
European-Non Finnish (NFE)
AF:
0.0129
AC:
14385
AN:
1111572
Other (OTH)
AF:
0.0159
AC:
962
AN:
60378
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.456
Heterozygous variant carriers
0
915
1830
2746
3661
4576
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
568
1136
1704
2272
2840
<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:
0.0171
AC:
2608
AN:
152086
Hom.:
43
Cov.:
31
AF XY:
0.0163
AC XY:
1215
AN XY:
74348
show subpopulations
African (AFR)
AF:
0.0306
AC:
1269
AN:
41460
American (AMR)
AF:
0.0133
AC:
204
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.0554
AC:
192
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5126
South Asian (SAS)
AF:
0.00601
AC:
29
AN:
4822
European-Finnish (FIN)
AF:
0.00444
AC:
47
AN:
10594
Middle Eastern (MID)
AF:
0.0137
AC:
4
AN:
292
European-Non Finnish (NFE)
AF:
0.0120
AC:
817
AN:
68008
Other (OTH)
AF:
0.0180
AC:
38
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
136
272
408
544
680
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
30
60
90
120
150
<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:
0.0143
Hom.:
14
Bravo
AF:
0.0197
Asia WGS
AF:
0.00433
AC:
15
AN:
3478
EpiCase
AF:
0.0151
EpiControl
AF:
0.0162

ClinVar

Significance: Benign
Submissions summary: Benign:7
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

not specified Benign:4
Apr 15, 2021
Athena Diagnostics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Feb 03, 2016
GeneDx
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

-
Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

-
Laboratory of Diagnostic Genome Analysis, Leiden University Medical Center (LUMC)
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Batten-Turner congenital myopathy Benign:1
Jan 13, 2018
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided Benign:1
-
Breakthrough Genomics, Breakthrough Genomics
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:not provided

- -

Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Benign:1
Feb 03, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.49
CADD
Benign
6.1
DANN
Benign
0.79
PhyloP100
1.9
Mutation Taster
=100/0
polymorphism (auto)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.050
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs78085922; hg19: chr7-143043304; API