chr1-210683316-G-A

Position:

• chr1-210683316-G-A

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_172362.3(KCNH1):​c.2935C>T​(p.Pro979Ser) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000197 in 152,042 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: 𝑓 0.000020 (0 hom., cov: 32)
• Consequence: KCNH1 NM_172362.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.81

Genes affected

KCNH1 (HGNC:6250): (potassium voltage-gated channel subfamily H member 1) Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. This gene encodes a member of the potassium channel, voltage-gated, subfamily H. This member is a pore-forming (alpha) subunit of a voltage-gated non-inactivating delayed rectifier potassium channel. It is activated at the onset of myoblast differentiation. The gene is highly expressed in brain and in myoblasts. Overexpression of the gene may confer a growth advantage to cancer cells and favor tumor cell proliferation. Alternative splicing of this gene results in two transcript variants encoding distinct isoforms. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCNH1. . Gene score misZ: 3.8156 (greater than the threshold 3.09). Trascript score misZ: 5.0674 (greater than threshold 3.09). The gene has 27 curated pathogenic missense variants (we use a threshold of 10). The gene has 72 curated benign missense variants. GenCC has associacion of the gene with KCNH1 associated disorder, Zimmermann-Laband syndrome, Temple-Baraitser syndrome, Zimmermann-Laband syndrome 1.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNH1	NM_172362.3	c.2935C>T	p.Pro979Ser	missense_variant	11/11	ENST00000271751.10	NP_758872.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNH1	ENST00000271751.10	c.2935C>T	p.Pro979Ser	missense_variant	11/11	2	NM_172362.3	ENSP00000271751.4

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152042 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000197

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 Cov.: 36

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152042 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74262

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.000197

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: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jan 17, 2023

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on KCNH1 protein function. This variant has not been reported in the literature in individuals affected with KCNH1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces proline, which is neutral and non-polar, with serine, which is neutral and polar, at codon 979 of the KCNH1 protein (p.Pro979Ser). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Pathogenic	0.26	D
BayesDel_noAF	Pathogenic	0.14
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T;.;.;T
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D;.;D;D
M_CAP	Pathogenic	0.80	D
MetaRNN	Uncertain	0.71	D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Benign	2.0	M;.;.;.
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	-2.0	N;.;.;.
REVEL	Uncertain	0.58
Sift	Pathogenic	0.0	D;.;.;.
Sift4G	Uncertain	0.033	D;.;.;.
Polyphen		1.0	D;.;.;.
Vest4		0.23
MutPred		0.15		Gain of phosphorylation at P979 (P = 0.0099);.;.;.;
MVP		0.97
MPC		0.70
ClinPred		0.99	D
GERP RS		5.1
Varity_R		0.41
gMVP		0.53

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

Publications

LitVar

Other links and lift over

dbSNP: rs1681319240; hg19: chr1-210856658; COSMIC: COSV55076302; COSMIC: COSV55076302;