rs199473521

Variant names:

• chr7-150951608-T-A
• rs199473521
• NM_000238.4:c.1785A>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PP2 PP3_Strong

The NM_000238.4(KCNH2):​c.1785A>T​(p.Lys595Asn) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as not provided (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K595E) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 34)
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 0.544
• Publications: 3 publications found

Genes affected

KCNH2 (HGNC:6251): (potassium voltage-gated channel subfamily H member 2) This gene encodes a component of a voltage-activated potassium channel found in cardiac muscle, nerve cells, and microglia. Four copies of this protein interact with one copy of the KCNE2 protein to form a functional potassium channel. Mutations in this gene can cause long QT syndrome type 2 (LQT2). Transcript variants encoding distinct isoforms have been identified. [provided by RefSeq, May 2022]

KCNH2 Gene-Disease associations (from GenCC):

• long QT syndrome

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• long QT syndrome 2

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• short QT syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: ClinGen, Orphanet
• short QT syndrome type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• Brugada syndrome

  Inheritance: AD Classification: MODERATE, NO_KNOWN Submitted by: ClinGen, Genomics England PanelApp

ACMG classification

Our verdict: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 16 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 18 uncertain in NM_000238.4
• 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 158 curated pathogenic missense variants (we use a threshold of 10). The gene has 38 curated benign missense variants. Gene score misZ: 3.3724 (above the threshold of 3.09). Trascript score misZ: 2.4846 (below the threshold of 3.09). GenCC associations: The gene is linked to long QT syndrome 2, Brugada syndrome, short QT syndrome type 1, short QT syndrome, long QT syndrome.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.975

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000238.4. 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
	KCNH2	NM_000238.4	MANE Select	c.1785A>T	p.Lys595Asn	missense	Exon 7 of 15	NP_000229.1	A0A090N8Q0
	KCNH2	NM_001406753.1		c.1497A>T	p.Lys499Asn	missense	Exon 5 of 13	NP_001393682.1	Q12809-7
	KCNH2	NM_172056.3		c.1785A>T	p.Lys595Asn	missense	Exon 7 of 9	NP_742053.1	Q12809-5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNH2	ENST00000262186.10	TSL:1 MANE Select	c.1785A>T	p.Lys595Asn	missense	Exon 7 of 15	ENSP00000262186.5	Q12809-1
	KCNH2	ENST00000330883.9	TSL:1	c.765A>T	p.Lys255Asn	missense	Exon 3 of 11	ENSP00000328531.4	Q12809-2
	KCNH2	ENST00000461280.2	TSL:1	n.1083A>T		non_coding_transcript_exon	Exon 3 of 5

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 34

GnomAD4 genome Cov.: 34

ClinVar

ClinVar submissions

Significance: not provided

Revision: no classification provided

Pathogenic	VUS	Benign	Condition
-	-	-	Congenital long QT syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
CardioboostArm	Uncertain	0.88
BayesDel_addAF	Pathogenic	0.21	D
BayesDel_noAF	Uncertain	0.070
CADD	Benign	23
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.93	D
Eigen	Benign	-0.43
Eigen_PC	Benign	-0.43
FATHMM_MKL	Benign	0.69	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Benign	1.9	L
PhyloP100		0.54
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-4.5	D
REVEL	Pathogenic	0.67
Sift	Benign	0.044	D
Sift4G	Benign	0.077	T
Polyphen		0.20	B
Vest4		0.89
MutPred		0.85		Loss of methylation at K595 (P = 0.0058)
MVP		0.96
MPC		2.3
ClinPred		0.98	D
GERP RS		1.3
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.60
gMVP		0.96
Mutation Taster		=6/94	disease causing

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: rs199473521; hg19: chr7-150648696;