9-2729480-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM1 PM2 BP4

The NM_133497.4(KCNV2):c.1391A>G(p.Tyr464Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,712 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNV2 NM_133497.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.319

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 Uncertain_significance. Variant got 3 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_133497.4
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.35803035).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNV2	NM_133497.4	c.1391A>G	p.Tyr464Cys	missense_variant	2/2	ENST00000382082.4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNV2	ENST00000382082.4	c.1391A>G	p.Tyr464Cys	missense_variant	2/2	1	NM_133497.4	P1
PUM3	ENST00000490444.2	c.*127-8948T>C		intron_variant, NMD_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000796 AC: 2 AN: 251386 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135866

Gnomad AFR exome AF: 0.0000615

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: 0.00000137 AC: 2 AN: 1461712 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727168

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

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.: 32

ExAC AF: 0.00000824 AC: 1

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

Invitae

Jun 20, 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. 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) performed at Invitae indicates that this missense variant is not expected to disrupt KCNV2 protein function. This variant has not been reported in the literature in individuals affected with KCNV2-related conditions. This variant is present in population databases (rs778822772, gnomAD 0.007%). This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 464 of the KCNV2 protein (p.Tyr464Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.086
BayesDel_addAF	Benign	-0.055	T
BayesDel_noAF	Benign	-0.14
Cadd	Benign	16
Dann	Benign	0.92
DEOGEN2	Uncertain	0.72	D
Eigen	Benign	-0.60
Eigen_PC	Benign	-0.47
FATHMM_MKL	Benign	0.68	D
LIST_S2	Benign	0.85	T
M_CAP	Benign	0.072	D
MetaRNN	Benign	0.36	T
MetaSVM	Uncertain	0.35	D
MutationAssessor	Benign	1.3	L
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-4.3	D
REVEL	Uncertain	0.44
Sift	Benign	0.16	T
Sift4G	Benign	0.23	T
Polyphen		0.0050	B
Vest4		0.17
MutPred		0.59		Loss of disorder (P = 0.0964);
MVP		0.79
MPC		0.018
ClinPred		0.12	T
GERP RS		0.0030
Varity_R		0.24
gMVP		0.95

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: rs778822772; hg19: chr9-2729480;