rs776842795

Positions:

• chr14-62981203-G-A
• chr14-62981203-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PP2 PP3_Moderate

The NM_139318.5(KCNH5):​c.611C>T​(p.Pro204Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,750 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. P204S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNH5 NM_139318.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.93

Genes affected

KCNH5 (HGNC:6254): (potassium voltage-gated channel subfamily H member 5) This gene encodes a member of voltage-gated potassium channels. Members of this family have diverse functions, including regulating neurotransmitter and hormone release, cardiac function, and cell volume. This protein is an outward-rectifying, noninactivating channel. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2013]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 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), KCNH5. . Gene score misZ 2.509 (greater than the threshold 3.09). Trascript score misZ 3.7308 (greater than threshold 3.09). GenCC has associacion of gene with infantile-onset epilepsy.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.868

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNH5	NM_139318.5	c.611C>T	p.Pro204Leu	missense_variant	6/11	ENST00000322893.12
KCNH5	NM_172375.3	c.611C>T	p.Pro204Leu	missense_variant	6/10
KCNH5	XM_047431275.1	c.611C>T	p.Pro204Leu	missense_variant	6/10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNH5	ENST00000322893.12	c.611C>T	p.Pro204Leu	missense_variant	6/11	1	NM_139318.5	P1
KCNH5	ENST00000420622.6	c.611C>T	p.Pro204Leu	missense_variant	6/10	1
KCNH5	ENST00000394964.3	n.776C>T		non_coding_transcript_exon_variant	6/7	1
KCNH5	ENST00000394968.2	c.437C>T	p.Pro146Leu	missense_variant	6/11	2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250672 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135472

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461750 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727178

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Early infantile epileptic encephalopathy with suppression bursts Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 28, 2021

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. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with KCNH5-related disease. This variant is present in population databases (rs776842795, ExAC 0.009%). This sequence change replaces proline with leucine at codon 204 of the KCNH5 protein (p.Pro204Leu). The proline residue is highly conserved and there is a moderate physicochemical difference between proline and leucine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.66	D;.;.
Eigen	Pathogenic	0.84
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.87	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.8	M;M;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-9.4	D;D;D
REVEL	Pathogenic	0.85
Sift	Uncertain	0.0050	D;D;D
Sift4G	Uncertain	0.021	D;D;D
Polyphen		1.0	D;D;D
Vest4		0.79
MutPred		0.50		Gain of catalytic residue at L208 (P = 0);Gain of catalytic residue at L208 (P = 0);.;
MVP		0.93
MPC		1.8
ClinPred		1.0	D
GERP RS		5.3
Varity_R		0.78
gMVP		0.83

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: rs776842795; hg19: chr14-63447921;