11-2445483-G-C

Variant names:

• chr11-2445483-G-C
• NM_000218.3:c.385G>C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_000218.3(KCNQ1):​c.385G>C​(p.Val129Leu) variant causes a missense, splice region change. The variant allele was found at a frequency of 0.00000208 in 1,442,186 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. V129I) has been classified as Benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense, splice_region
• Scores: Splicing: ADA: 0.4570
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.73

Genes affected

KCNQ1 (HGNC:6294): (potassium voltage-gated channel subfamily Q member 1) This gene encodes a voltage-gated potassium channel required for repolarization phase of the cardiac action potential. This protein can form heteromultimers with two other potassium channel proteins, KCNE1 and KCNE3. Mutations in this gene are associated with hereditary long QT syndrome 1 (also known as Romano-Ward syndrome), Jervell and Lange-Nielsen syndrome, and familial atrial fibrillation. This gene exhibits tissue-specific imprinting, with preferential expression from the maternal allele in some tissues, and biallelic expression in others. This gene is located in a region of chromosome 11 amongst other imprinted genes that are associated with Beckwith-Wiedemann syndrome (BWS), and itself has been shown to be disrupted by chromosomal rearrangements in patients with BWS. Alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Aug 2011]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a helix (size 21) in uniprot entity KCNQ1_HUMAN there are 12 pathogenic changes around while only 1 benign (92%) in NM_000218.3
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ1	NM_000218.3	c.385G>C	p.Val129Leu	missense_variant, splice_region_variant	Exon 1 of 16	ENST00000155840.12	NP_000209.2
KCNQ1	NM_001406836.1	c.385G>C	p.Val129Leu	missense_variant, splice_region_variant	Exon 1 of 15		NP_001393765.1
KCNQ1	NM_001406837.1	c.23G>C	p.Arg8Pro	missense_variant, splice_region_variant	Exon 1 of 17		NP_001393766.1
KCNQ1	NM_001406838.1	c.385G>C	p.Val129Leu	missense_variant, splice_region_variant	Exon 1 of 11		NP_001393767.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ1	ENST00000155840.12	c.385G>C	p.Val129Leu	missense_variant, splice_region_variant	Exon 1 of 16	1	NM_000218.3	ENSP00000155840.2
KCNQ1	ENST00000345015.4	n.162G>C		splice_region_variant, non_coding_transcript_exon_variant	Exon 1 of 3	1
KCNQ1	ENST00000496887.7	c.124G>C	p.Val42Leu	missense_variant, splice_region_variant	Exon 2 of 16	5		ENSP00000434560.2
KCNQ1	ENST00000646564.2	c.385G>C	p.Val129Leu	missense_variant, splice_region_variant	Exon 1 of 11			ENSP00000495806.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000208 AC: 3 AN: 1442186 Hom.: 0 Cov.: 31 AF XY: 0.00000279 AC XY: 2 AN XY: 717520

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.91
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.89	.;D;.
Eigen	Benign	0.13
Eigen_PC	Benign	0.18
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Benign	0.69	T;T;D
M_CAP	Pathogenic	0.41	D
MetaRNN	Uncertain	0.71	D;D;D
MetaSVM	Pathogenic	0.86	D
MutationAssessor	Benign	2.0	.;M;.
PrimateAI	Uncertain	0.73	T
PROVEAN	Benign	-2.1	N;N;.
REVEL	Pathogenic	0.75
Sift	Uncertain	0.020	D;D;.
Sift4G	Benign	0.10	T;D;.
Polyphen		0.10	.;B;.
Vest4		0.41
MutPred		0.66		.;Loss of catalytic residue at V129 (P = 0.1552);.;
MVP		0.96
MPC		1.2
ClinPred		0.88	D
GERP RS		3.2
Varity_R		0.64
gMVP		0.94

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.46
dbscSNV1_RF	Benign	0.54
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

No publications associated with this variant yet.

Other links and lift over

hg19: chr11-2466713;