KCNQ1 p.His126Leu

Variant names:

• chr11-2445475-A-T
• rs794728579
• NM_000218.3:c.377A>T
• KCNQ1 p.His126Leu

Your query was ambiguous. Multiple possible variants found:

• chr11-2445475-A-T
• chr11-2445475-AC-TT
• chr11-2445475-AC-TA
• chr11-2445475-AC-TG
• chr11-2445474-CAC-TTA
• chr11-2445474-CAC-TTG

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP2 PP3_Moderate PP5

The NM_000218.3(KCNQ1):​c.377A>T​(p.His126Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000139 in 1,442,944 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H126Y) has been classified as Uncertain significance. The gene KCNQ1 is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNQ1 NM_000218.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 6.46
• Publications: 6 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: Labcorp Genetics (formerly Invitae), G2P
• 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: Likely_pathogenic. The variant received 8 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, 16 uncertain in NM_000218.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 212 curated pathogenic missense variants (we use a threshold of 10). The gene has 12 curated benign missense variants. Gene score misZ: 1.8321 (below the threshold of 3.09). Trascript score misZ: 0.90233 (below the threshold of 3.09). GenCC associations: The gene is linked to short QT syndrome, Jervell and Lange-Nielsen syndrome 1, long QT syndrome 1, familial atrial fibrillation, short QT syndrome type 2, long QT syndrome, atrial fibrillation, familial, 3, Jervell and Lange-Nielsen syndrome, hypertrophic cardiomyopathy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.92
• PP5: Variant 11-2445475-A-T is Pathogenic according to our data. Variant chr11-2445475-A-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 200911.

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.377A>T	p.His126Leu	missense	Exon 1 of 16	NP_000209.2
	KCNQ1	NM_001406836.1		c.377A>T	p.His126Leu	missense	Exon 1 of 15	NP_001393765.1
	KCNQ1	NM_001406838.1		c.377A>T	p.His126Leu	missense	Exon 1 of 11	NP_001393767.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNQ1	ENST00000155840.12	TSL:1 MANE Select	c.377A>T	p.His126Leu	missense	Exon 1 of 16	ENSP00000155840.2	P51787-1
	KCNQ1	ENST00000345015.4	TSL:1	n.154A>T		non_coding_transcript_exon	Exon 1 of 3
	KCNQ1	ENST00000910997.1		c.377A>T	p.His126Leu	missense	Exon 1 of 16	ENSP00000581056.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000139 AC: 2 AN: 1442944 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 717972

African (AFR) AF: 0.00 AC: 0 AN: 33452

American (AMR) AF: 0.00 AC: 0 AN: 44430

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26040

East Asian (EAS) AF: 0.00 AC: 0 AN: 39606

South Asian (SAS) AF: 0.00 AC: 0 AN: 85742

European-Finnish (FIN) AF: 0.0000540 AC: 2 AN: 37008

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5724

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110862

Other (OTH) AF: 0.00 AC: 0 AN: 60080

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Conflicting classifications of pathogenicity

Revision: criteria provided, conflicting classifications

Pathogenic	VUS	Benign	Condition
-	1	-	Long QT syndrome (1)
1	-	-	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
CardioboostArm	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.43
CADD	Pathogenic	30
DANN	Benign	0.96
DEOGEN2	Pathogenic	0.96	D
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.54
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.86	D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.0	M
PhyloP100		6.5
PrimateAI	Pathogenic	0.80	D
PROVEAN	Pathogenic	-8.1	D
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D
Sift4G	Uncertain	0.0030	D
PromoterAI		0.029	Neutral
Varity_R		0.99
gMVP		0.98
Mutation Taster		=4/96	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

dbSNP: rs794728579;

hg19: chr11-2466705;