7-143351935-C-T

Variant names:

• chr7-143351935-C-T
• rs776873546
• NM_000083.3:c.2937C>T

Variant summary

Our verdict is Benign. The variant received -11 ACMG points: 0P and 11B. BP4_Moderate BP6_Very_Strong BP7

The NM_000083.3(CLCN1):​c.2937C>T​(p.Asp979Asp) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000291 in 1,613,340 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.000046 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000027 (0 hom.)
• Consequence: CLCN1 NM_000083.3 synonymous
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: -2.15
• Publications: 0 publications found

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

ACMG classification

Our verdict: Benign. The variant received -11 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.41).
• BP6: Variant 7-143351935-C-T is Benign according to our data. Variant chr7-143351935-C-T is described in ClinVar as Likely_benign. ClinVar VariationId is 462842.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=-2.15 with no splicing effect.

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.2937C>T	p.Asp979Asp	synonymous	Exon 23 of 23	NP_000074.3	P35523
	CLCN1	NR_046453.2		n.2892C>T		non_coding_transcript_exon	Exon 22 of 22

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	CLCN1	ENST00000343257.7	TSL:1 MANE Select	c.2937C>T	p.Asp979Asp	synonymous	Exon 23 of 23	ENSP00000339867.2	P35523
	CLCN1	ENST00000650516.2		c.2937C>T	p.Asp979Asp	synonymous	Exon 23 of 23	ENSP00000498052.2	A0A3B3IU72
	CLCN1	ENST00000958857.1		c.2850C>T	p.Asp950Asp	synonymous	Exon 22 of 22	ENSP00000628916.1

Frequencies

GnomAD3 genomes AF: 0.0000460 AC: 7 AN: 152134 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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: 0.0000735

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000319 AC: 8 AN: 251076 AF XY: 0.0000368

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000579

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000440

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000274 AC: 40 AN: 1461088 Hom.: 0 Cov.: 32 AF XY: 0.0000220 AC XY: 16 AN XY: 726850

African (AFR) AF: 0.00 AC: 0 AN: 33450

American (AMR) AF: 0.0000447 AC: 2 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.0000504 AC: 2 AN: 39700

South Asian (SAS) AF: 0.0000348 AC: 3 AN: 86220

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5116

European-Non Finnish (NFE) AF: 0.0000297 AC: 33 AN: 1112010

Other (OTH) AF: 0.00 AC: 0 AN: 60314

GnomAD4 genome AF: 0.0000460 AC: 7 AN: 152252 Hom.: 0 Cov.: 32 AF XY: 0.0000403 AC XY: 3 AN XY: 74432

African (AFR) AF: 0.00 AC: 0 AN: 41534

American (AMR) AF: 0.000131 AC: 2 AN: 15294

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5174

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10614

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000735 AC: 5 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2112

Alfa AF: 0.000102 Hom.: 0

Bravo AF: 0.0000340

ClinVar

ClinVar submissions

Significance: Likely benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Congenital myotonia, autosomal recessive form;C2936781:Congenital myotonia, autosomal dominant form (1)
-	-	1	not specified (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.41
CADD	Benign	0.55
DANN	Benign	0.87
PhyloP100		-2.2
Mutation Taster		=100/0	polymorphism

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

Other links and lift over

dbSNP: rs776873546; hg19: chr7-143049028; COSMIC: COSV100578570; COSMIC: COSV100578570;