rs921731349

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 0P and 3B. BP4_ModerateBP7

The NM_000083.3(CLCN1):​c.432G>A​(p.Gln144=) variant causes a splice region, synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000867 in 1,613,932 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 31)
Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

CLCN1
NM_000083.3 splice_region, synonymous

Scores

2
Splicing: ADA: 0.0009579
2

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.23
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]

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -3 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.42).
BP7
Synonymous conserved (PhyloP=2.22 with no splicing effect.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
CLCN1NM_000083.3 linkuse as main transcriptc.432G>A p.Gln144= splice_region_variant, synonymous_variant 3/23 ENST00000343257.7 NP_000074.3
CLCN1NR_046453.2 linkuse as main transcriptn.534G>A splice_region_variant, non_coding_transcript_exon_variant 3/22

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
CLCN1ENST00000343257.7 linkuse as main transcriptc.432G>A p.Gln144= splice_region_variant, synonymous_variant 3/231 NM_000083.3 ENSP00000339867 P4
CLCN1ENST00000432192.6 linkuse as main transcriptc.201G>A p.Gln67= splice_region_variant, synonymous_variant, NMD_transcript_variant 2/231 ENSP00000395949
CLCN1ENST00000650516.2 linkuse as main transcriptc.432G>A p.Gln144= splice_region_variant, synonymous_variant 3/23 ENSP00000498052 A2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152102
Hom.:
0
Cov.:
31
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
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:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
0.00000889
AC:
13
AN:
1461830
Hom.:
0
Cov.:
33
AF XY:
0.0000110
AC XY:
8
AN XY:
727222
show subpopulations
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:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000117
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152102
Hom.:
0
Cov.:
31
AF XY:
0.0000135
AC XY:
1
AN XY:
74290
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Bravo
AF:
0.0000113

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpJun 11, 2019This sequence change affects codon 144 of the CLCN1 mRNA. It is a 'silent' change, meaning that it does not change the encoded amino acid sequence of the CLCN1 protein. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with CLCN1-related disease. ClinVar contains an entry for this variant (Variation ID: 531759). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant is not likely to affect RNA splicing, but this prediction has not been confirmed by published transcriptional studies. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.42
CADD
Benign
16
DANN
Benign
0.89

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.00096
dbscSNV1_RF
Benign
0.082
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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs921731349; hg19: chr7-143017887; API