rs80356687

chr7-143324442-C-Gchr7-143324442-C-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000083.3(CLCN1):c.803C>G(p.Thr268Arg) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. T268M) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: CLCN1 NM_000083.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 6.14

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]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 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 chr7-143324442-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 21047.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.958

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CLCN1	NM_000083.3	c.803C>G	p.Thr268Arg	missense_variant	7/23	ENST00000343257.7
CLCN1	NR_046453.2	n.908C>G		non_coding_transcript_exon_variant	7/22

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CLCN1	ENST00000343257.7	c.803C>G	p.Thr268Arg	missense_variant	7/23	1	NM_000083.3	P4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.82
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.43
Cadd	Pathogenic	30
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.86	D
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D
M_CAP	Uncertain	0.25	D
MetaRNN	Pathogenic	0.96	D
MetaSVM	Pathogenic	0.99	D
MutationAssessor	Benign	2.0	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.79	T
PROVEAN	Uncertain	-2.8	D
REVEL	Pathogenic	0.89
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0040	D
Polyphen		1.0	D
Vest4		0.98
MutPred		0.81		Gain of methylation at T268 (P = 0.1273);
MVP		0.98
MPC		0.78
ClinPred		0.99	D
GERP RS		4.8
Varity_R		0.88
gMVP		0.96

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

LitVar

Other links and lift over

dbSNP: rs80356687; hg19: chr7-143021535;