rs371521698

chr12-5044848-G-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PP3_Moderate BS2

The NM_002234.4(KCNA5):c.701G>T(p.Arg234Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000162 in 1,613,862 control chromosomes in the GnomAD database, including 1 homozygotes. 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. R234S) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.00011 (0 hom., cov: 32)
  • Exomes 𝑓: 0.00017 (1 hom.)
• Consequence: KCNA5 NM_002234.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:5
• Conservation: PhyloP100: 2.68

Genes affected

KCNA5 (HGNC:6224): (potassium voltage-gated channel subfamily A member 5) Potassium channels represent the most complex class of voltage-gated ino 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 contains six membrane-spanning domains with a shaker-type repeat in the fourth segment. It belongs to the delayed rectifier class, the function of which could restore the resting membrane potential of beta cells after depolarization and thereby contribute to the regulation of insulin secretion. This gene is intronless, and the gene is clustered with genes KCNA1 and KCNA6 on chromosome 12. Defects in this gene are a cause of familial atrial fibrillation type 7 (ATFB7). [provided by RefSeq, May 2012]

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.846
• BS2: High AC in GnomAd at 17 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNA5	NM_002234.4	c.701G>T	p.Arg234Leu	missense_variant	1/1	ENST00000252321.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNA5	ENST00000252321.5	c.701G>T	p.Arg234Leu	missense_variant	1/1		NM_002234.4	P1

Frequencies

GnomAD3 genomes AF: 0.000112 AC: 17 AN: 152110 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000483

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: 0.000221

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000398 AC: 10 AN: 251258 Hom.: 0 AF XY: 0.0000294 AC XY: 4 AN XY: 135846

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: 0.0000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.000168 AC: 245 AN: 1461752 Hom.: 1 Cov.: 32 AF XY: 0.000166 AC XY: 121 AN XY: 727194

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: 0.000217

Gnomad4 OTH exome AF: 0.0000497

GnomAD4 genome AF: 0.000112 AC: 17 AN: 152110 Hom.: 0 Cov.: 32 AF XY: 0.000121 AC XY: 9 AN XY: 74298

Gnomad4 AFR AF: 0.0000483

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: 0.000221

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000123 Hom.: 0

Bravo AF: 0.0000869

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000233 AC: 2

ExAC AF: 0.0000412 AC: 5

EpiCase AF: 0.000164

EpiControl AF: 0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Atrial fibrillation, familial, 7 Uncertain:3

Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -
Uncertain significance, criteria provided, single submitter	clinical testing	Fulgent Genetics, Fulgent Genetics	Jul 26, 2021	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Feb 01, 2024	This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 234 of the KCNA5 protein (p.Arg234Leu). This variant is present in population databases (rs371521698, gnomAD 0.01%). This variant has not been reported in the literature in individuals affected with KCNA5-related conditions. ClinVar contains an entry for this variant (Variation ID: 191461). 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 KCNA5 protein function with a negative predictive value of 80%. 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. -

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Aug 31, 2022	Has not been previously published as pathogenic or benign to our knowledge; In silico analysis supports that this missense variant has a deleterious effect on protein structure/function -
Uncertain significance, criteria provided, single submitter	research	Biesecker Lab/Clinical Genomics Section, National Institutes of Health	Jun 24, 2013	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.69
BayesDel_addAF	Benign	-0.085	T
BayesDel_noAF	Uncertain	-0.050
Cadd	Uncertain	24
Dann	Uncertain	1.0
DEOGEN2	Uncertain	0.67	D
Eigen	Uncertain	0.21
Eigen_PC	Benign	0.069
FATHMM_MKL	Benign	0.61	D
LIST_S2	Uncertain	0.92	D
M_CAP	Uncertain	0.22	D
MetaRNN	Pathogenic	0.85	D
MetaSVM	Uncertain	-0.025	T
MutationAssessor	Uncertain	2.6	M
MutationTaster	Benign	0.99	D
PrimateAI	Benign	0.46	T
PROVEAN	Pathogenic	-5.9	D
REVEL	Uncertain	0.46
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Polyphen		1.0	D
Vest4		0.66
MVP		0.85
MPC		1.6
ClinPred		0.90	D
GERP RS		3.0
Varity_R		0.56
gMVP		0.81

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: rs371521698; hg19: chr12-5154014;