Genetic Variant NM_012284.3:c.2707C>T (chr12-49557408-C-T) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_012284.3(KCNH3):c.2707C>T(p.Arg903Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000437 in 1,600,770 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000035 ( 0 hom. )

Consequence

KCNH3
NM_012284.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 2.18

Variant links:

Genes affected

KCNH3 (HGNC:6252): (potassium voltage-gated channel subfamily H member 3) The protein encoded by this gene is a voltage-gated potassium channel alpha subunit predominantly expressed in the forebrain. Studies in mice have found that cognitive function increases when this gene is knocked out. In humans, the encoded protein has been shown to be capable of binding glycoprotein 120 of the human immunodeficiency virus type 1 (HIV-1) envelope. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Sep 2015]

KCNH3 links:

MCRS1 (HGNC:6960): (microspherule protein 1) Enables RNA binding activity and telomerase inhibitor activity. Involved in histone H4 acetylation; negative regulation of DNA metabolic process; and positive regulation of protein localization to nucleolus. Located in cytoplasm; nucleolus; and nucleoplasm. Part of Ino80 complex; MLL1 complex; and histone acetyltransferase complex. [provided by Alliance of Genome Resources, Apr 2022]

MCRS1 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BS2

High AC in GnomAdExome4 at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNH3	NM_012284.3 link	c.2707C>T	p.Arg903Cys	missense_variant	Exon 15 of 15	ENST00000257981.7	NP_036416.1	Q9ULD8
KCNH3	NM_001314030.2 link	c.2527C>T	p.Arg843Cys	missense_variant	Exon 15 of 15		NP_001300959.1	Q9ULD8
KCNH3	XM_011538085.3 link	c.2740C>T	p.Arg914Cys	missense_variant	Exon 15 of 15		XP_011536387.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNH3	ENST00000257981.7 link	c.2707C>T	p.Arg903Cys	missense_variant	Exon 15 of 15	1	NM_012284.3	ENSP00000257981.5		Q9ULD8

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152198

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.00000345

AC:

AN:

1448572

Hom.:

Cov.:

AF XY:

0.00000278

AC XY:

AN XY:

718624

show subpopulations

Gnomad4 AFR exome

AF:

0.0000300

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000362

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152198

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74366

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.0000654

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000264

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Nov 14, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.2707C>T (p.R903C) alteration is located in exon 15 (coding exon 15) of the KCNH3 gene. This alteration results from a C to T substitution at nucleotide position 2707, causing the arginine (R) at amino acid position 903 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.15

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.19

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.15

Eigen

Uncertain

0.27

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Benign

0.62

LIST_S2

Uncertain

0.88

M_CAP

Pathogenic

0.46

MetaRNN

Uncertain

0.51

MetaSVM

Pathogenic

1.0

MutationAssessor

Benign

0.55

PrimateAI

Uncertain

0.57

PROVEAN

Benign

-1.0

REVEL

Pathogenic

0.66

Sift

Benign

0.059

Sift4G

Benign

0.16

Polyphen

1.0

Vest4

0.31

MVP

0.89

MPC

0.66

ClinPred

0.94

GERP RS

4.0

Varity_R

0.11

gMVP

0.58

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over