9-2729464-G-T

Position:

• chr9-2729464-G-T

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_133497.4(KCNV2):​c.1375G>T​(p.Gly459Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,486 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging 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. G459D) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: KCNV2 NM_133497.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.92

Genes affected

KCNV2 (HGNC:19698): (potassium voltage-gated channel modifier subfamily V member 2) 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 voltage-gated channel subfamily V. This member is identified as a 'silent subunit', and it does not form homomultimers, but forms heteromultimers with several other subfamily members. Through obligatory heteromerization, it exerts a function-altering effect on other potassium channel subunits. This protein is strongly expressed in pancreas and has a weaker expression in several other tissues. [provided by RefSeq, Jul 2008]

PUM3 (HGNC:29676): (pumilio RNA binding family member 3) Enables RNA binding activity. Involved in regulation of protein ADP-ribosylation. Located in chromosome; endoplasmic reticulum; and nuclear lumen. [provided by Alliance of Genome Resources, Apr 2022]

ACMG classification

Verdict is Pathogenic. Variant got 10 ACMG points.

• PM1: In a short_sequence_motif Selectivity filter (size 5) in uniprot entity KCNV2_HUMAN there are 5 pathogenic changes around while only 0 benign (100%) in NM_133497.4
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr9-2729465-G-A is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNV2	NM_133497.4	c.1375G>T	p.Gly459Cys	missense_variant	2/2	ENST00000382082.4	NP_598004.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNV2	ENST00000382082.4	c.1375G>T	p.Gly459Cys	missense_variant	2/2	1	NM_133497.4	ENSP00000371514	P1
PUM3	ENST00000490444.2	c.*127-8932C>A		intron_variant, NMD_transcript_variant		5		ENSP00000474467

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251280 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135806

Gnomad AFR exome AF: 0.0000615

Gnomad AMR exome AF: 0.00

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: 0.00000274 AC: 4 AN: 1461486 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727068

Gnomad4 AFR exome AF: 0.0000299

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: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000370 Hom.: 0

Bravo AF: 0.0000113

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 27, 2022

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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). This missense change has been observed in individual(s) with KCNV2-related conditions (PMID: 33309813). This variant is present in population databases (no rsID available, gnomAD 0.007%). This sequence change replaces glycine, which is neutral and non-polar, with cysteine, which is neutral and slightly polar, at codon 459 of the KCNV2 protein (p.Gly459Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	33
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.91	D
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.79	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.90	D
MutationAssessor	Pathogenic	4.9	H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-8.5	D
REVEL	Pathogenic	0.98
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.97
MutPred		0.91		Gain of sheet (P = 0.0344);
MVP		0.99
MPC		0.14
ClinPred		1.0	D
GERP RS		5.4
Varity_R		0.98
gMVP		0.99

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: rs1256529152; hg19: chr9-2729464;