chr7-150974720-G-T

Variant names:

• chr7-150974720-G-T
• rs121912515
• NM_000238.4:c.298C>A

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BP4_Moderate BP7 BS2_Supporting

The NM_000238.4(KCNH2):​c.298C>A​(p.Arg100Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000505 in 1,385,408 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R100R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000051 (0 hom.)
• Consequence: KCNH2 NM_000238.4 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.738
• Publications: 9 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), Ambry Genetics, G2P
• short QT syndrome

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: Orphanet, ClinGen
• 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_benign. The variant received -4 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.41).
• BP7: Synonymous conserved (PhyloP=0.738 with no splicing effect.
• BS2: High AC in GnomAdExome4 at 7 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH2	NM_000238.4	c.298C>A	p.Arg100Arg	synonymous_variant	Exon 2 of 15	ENST00000262186.10	NP_000229.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNH2	ENST00000262186.10	c.298C>A	p.Arg100Arg	synonymous_variant	Exon 2 of 15	1	NM_000238.4	ENSP00000262186.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000925 AC: 2 AN: 216284 AF XY: 0.0000167

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: 0.0000217

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000505 AC: 7 AN: 1385408 Hom.: 0 Cov.: 34 AF XY: 0.00000727 AC XY: 5 AN XY: 687814

African (AFR) AF: 0.00 AC: 0 AN: 31006

American (AMR) AF: 0.00 AC: 0 AN: 41402

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 23250

East Asian (EAS) AF: 0.00 AC: 0 AN: 34814

South Asian (SAS) AF: 0.00 AC: 0 AN: 84130

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 47076

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 3984

European-Non Finnish (NFE) AF: 0.00000657 AC: 7 AN: 1064666

Other (OTH) AF: 0.00 AC: 0 AN: 55080

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.41
CADD	Benign	15
DANN	Benign	0.91
PhyloP100		0.74

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: rs121912515; hg19: chr7-150671808;