7-150958197-C-T

Variant names:

• chr7-150958197-C-T
• rs1220897906
• NM_000238.4:c.778G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_000238.4(KCNH2):​c.778G>A​(p.Ala260Thr) 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 benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A260V) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: KCNH2 NM_000238.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.349
• Publications: 0 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: Uncertain_significance. The variant received 2 ACMG points.

• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.35329035).

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.778G>A	p.Ala260Thr	missense	Exon 4 of 15	NP_000229.1	A0A090N8Q0
	KCNH2	NM_001406753.1		c.490G>A	p.Ala164Thr	missense	Exon 2 of 13	NP_001393682.1	Q12809-7
	KCNH2	NM_172056.3		c.778G>A	p.Ala260Thr	missense	Exon 4 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.778G>A	p.Ala260Thr	missense	Exon 4 of 15	ENSP00000262186.5	Q12809-1
	KCNH2	ENST00000713710.1		c.778G>A	p.Ala260Thr	missense	Exon 4 of 15	ENSP00000519013.1	A0AAQ5BGR0
	KCNH2	ENST00000713701.1		c.478G>A	p.Ala160Thr	missense	Exon 3 of 14	ENSP00000519004.1	A0AAQ5BGQ9

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1211296 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 589622

African (AFR) AF: 0.00 AC: 0 AN: 24416

American (AMR) AF: 0.00 AC: 0 AN: 15146

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 18692

East Asian (EAS) AF: 0.00 AC: 0 AN: 26548

South Asian (SAS) AF: 0.00 AC: 0 AN: 51436

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 29534

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3480

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 992482

Other (OTH) AF: 0.00 AC: 0 AN: 49562

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Long QT syndrome (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.069
CardioboostArm	Benign	0.0066
BayesDel_addAF	Pathogenic	0.18	D
BayesDel_noAF	Uncertain	0.020
CADD	Benign	22
DANN	Benign	0.97
DEOGEN2	Benign	0.36	T
Eigen	Benign	-0.39
Eigen_PC	Benign	-0.44
FATHMM_MKL	Benign	0.088	N
LIST_S2	Benign	0.69	T
M_CAP	Pathogenic	0.97	D
MetaRNN	Benign	0.35	T
MetaSVM	Uncertain	0.27	D
MutationAssessor	Benign	0.49	N
PhyloP100		0.35
PrimateAI	Pathogenic	0.88	D
PROVEAN	Benign	-0.76	N
REVEL	Uncertain	0.60
Sift	Benign	0.17	T
Sift4G	Benign	0.67	T
Polyphen		0.95	P
Vest4		0.23
MutPred		0.36		Gain of phosphorylation at A260 (P = 0.0275)
MVP		0.94
MPC		0.98
ClinPred		0.22	T
GERP RS		3.6
Varity_R		0.070
gMVP		0.50
Mutation Taster		=86/14	polymorphism

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

Other links and lift over

dbSNP: rs1220897906; hg19: chr7-150655285;