Genetic Variant KCNAB2:p.Glu20Gly (chr1-6051595-A-G) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 2P and 6B. PM1BP4_ModerateBS2

The NM_001199862.2(KCNAB2):c.59A>G(p.Glu20Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000274 in 1,534,766 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000027 ( 0 hom. )

Consequence

KCNAB2
NM_001199862.2 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 8.54

Variant links:

Genes affected

KCNAB2 (HGNC:6229): (potassium voltage-gated channel subfamily A regulatory beta subunit 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. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shaker-related subfamily. This member is one of the beta subunits, which are auxiliary proteins associating with functional Kv-alpha subunits. This member alters functional properties of the KCNA4 gene product. Alternative splicing of this gene results in multiple transcript variants encoding distinct isoforms. [provided by RefSeq, Dec 2010]

KCNAB2 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PM1

In a modified_residue Phosphoserine (size 0) in uniprot entity KCAB2_HUMAN

BP4

Computational evidence support a benign effect (MetaRNN=0.13004929).

BS2

High AC in GnomAdExome4 at 38 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNAB2	NM_001199862.2 link	c.59A>G	p.Glu20Gly	missense_variant	Exon 2 of 16	ENST00000378083.8	NP_001186791.1	Q13303-3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNAB2	ENST00000378083.8 link	c.59A>G	p.Glu20Gly	missense_variant	Exon 2 of 16	2	NM_001199862.2	ENSP00000367323.3		Q13303-3

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152222

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000150

AC:

AN:

133612

Hom.:

AF XY:

0.0000137

AC XY:

AN XY:

72738

show subpopulations

Gnomad AFR exome

AF:

0.00

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:

0.0000384

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000275

AC:

AN:

1382544

Hom.:

Cov.:

AF XY:

0.0000249

AC XY:

AN XY:

682182

show subpopulations

Gnomad4 AFR exome

AF:

0.0000317

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000126

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000325

Gnomad4 OTH exome

AF:

0.0000173

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152222

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74374

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000588

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000113

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000519

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jul 26, 2022

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.59A>G (p.E20G) alteration is located in exon 2 (coding exon 1) of the KCNAB2 gene. This alteration results from a A to G substitution at nucleotide position 59, causing the glutamic acid (E) at amino acid position 20 to be replaced by a glycine (G). 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

BayesDel_addAF

Benign

-0.21

BayesDel_noAF

Benign

-0.51

CADD

Uncertain

DANN

Uncertain

1.0

Eigen

Benign

0.035

Eigen_PC

Benign

0.19

FATHMM_MKL

Uncertain

0.91

LIST_S2

Benign

0.45

M_CAP

Uncertain

0.098

MetaRNN

Benign

0.13

MetaSVM

Benign

-1.0

PrimateAI

Uncertain

0.56

PROVEAN

Benign

-0.47

REVEL

Benign

0.10

Sift

Uncertain

0.0070

Sift4G

Uncertain

0.052

Polyphen

0.017

Vest4

0.21

MutPred

0.19

Gain of loop (P = 0.0435);

MVP

0.11

MPC

1.2

ClinPred

0.93

GERP RS

5.3

gMVP

0.57

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

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