NM_000218.3:c.1017_1019delCTT

Variant names:

• chr11-2583526-CCTT-C
• rs397508068
• NM_000218.3:c.1017_1019delCTT

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PS3 PM1 PM2 PM4_Supporting PP5_Very_Strong

The NM_000218.3(KCNQ1):​c.1017_1019delCTT​(p.Phe340del) variant causes a disruptive inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,316 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV005426327: A functional study has shown that this variant causes a reduction of channel current amplitudes when expressed in Xenopus oocytes (PMID:15950200)." and additional evidence is available in ClinVar. Synonymous variant affecting the same amino acid position (i.e. F339F) has been classified as Likely benign. The gene KCNQ1 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 disruptive_inframe_deletion
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 7.52
• Publications: 2 publications found

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]

KCNQ1 Gene-Disease associations (from GenCC):

• long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 1

  Inheritance: AD, AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• Jervell and Lange-Nielsen syndrome

  Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
• Jervell and Lange-Nielsen syndrome 1

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: G2P, Labcorp Genetics (formerly Invitae)
• atrial fibrillation, familial, 3

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• short QT syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: ClinGen, Orphanet
• short QT syndrome type 2

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P
• familial atrial fibrillation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Jervell and Lange-Nielsen syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• hypertrophic cardiomyopathy

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Specifications for KCNQ1 are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 17 ACMG points.

• PS3: PS3 evidence extracted from ClinVar submissions: SCV005426327: A functional study has shown that this variant causes a reduction of channel current amplitudes when expressed in Xenopus oocytes (PMID: 15950200).; SCV000234577: Published functional studies suggest a damaging effect via reduced potassium channel function (Thomas et al., 2005); SCV000738227: This alteration was suggested to attenuate channel activity (Thomas D et al. Cardiovasc. Res., 2005 Aug;67:487-97; Moss AJ et al. Circulation, 2007 May;115:2481-9).; SCV006061515: A functional study has shown that this variant causes a reduction of channel current amplitudes when expressed in Xenopus oocytes (PMID: 15950200).
• PM1: In a hotspot region, there are 20 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000218.3
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_000218.3. Strenght limited to Supporting due to length of the change: 1aa.
• PP5: Variant 11-2583526-CCTT-C is Pathogenic according to our data. Variant chr11-2583526-CCTT-C is described in ClinVar as Pathogenic. ClinVar VariationId is 52930.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000218.3. 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
	KCNQ1	NM_000218.3	MANE Select	c.1017_1019delCTT	p.Phe340del	disruptive_inframe_deletion	Exon 7 of 16	NP_000209.2
	KCNQ1	NM_001406836.1		c.1017_1019delCTT	p.Phe340del	disruptive_inframe_deletion	Exon 7 of 15	NP_001393765.1
	KCNQ1	NM_001406837.1		c.747_749delCTT	p.Phe250del	disruptive_inframe_deletion	Exon 8 of 17	NP_001393766.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	ENST00000155840.12	TSL:1 MANE Select	c.1017_1019delCTT	p.Phe340del	disruptive_inframe_deletion	Exon 7 of 16	ENSP00000155840.2	P51787-1
	KCNQ1	ENST00000335475.6	TSL:1	c.636_638delCTT	p.Phe213del	disruptive_inframe_deletion	Exon 7 of 16	ENSP00000334497.5	P51787-2
	KCNQ1	ENST00000910997.1		c.1014_1016delCTT	p.Phe339del	disruptive_inframe_deletion	Exon 7 of 16	ENSP00000581056.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251304 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461316 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 726974

African (AFR) AF: 0.00 AC: 0 AN: 33462

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26130

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53340

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111572

Other (OTH) AF: 0.00 AC: 0 AN: 60374

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	Long QT syndrome (4)
2	-	-	Cardiovascular phenotype (2)
1	-	-	Beckwith-Wiedemann syndrome;C1837014:Atrial fibrillation, familial, 3;C1865019:Short QT syndrome type 2;C4551509:Jervell and Lange-Nielsen syndrome 1;C4551647:Long QT syndrome 1 (1)
1	-	-	Cardiac arrhythmia (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.5
Mutation Taster		=6/94	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs397508068; hg19: chr11-2604756;