rs767881978

chr12-5045876-C-T

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM4 BS2

The NM_002234.4(KCNA5):c.1729C>T(p.Arg577Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000821 in 1,461,796 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 (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: KCNA5 NM_002234.4 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.918

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.

• PM4: Stoplost variant in NM_002234.4 Downstream stopcodon found after 702 codons.
• BS2: High AC in GnomAdExome at 7 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNA5	NM_002234.4	c.1729C>T	p.Arg577Ter	stop_gained	1/1	ENST00000252321.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNA5	ENST00000252321.5	c.1729C>T	p.Arg577Ter	stop_gained	1/1		NM_002234.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000279 AC: 7 AN: 250866 Hom.: 0 AF XY: 0.0000295 AC XY: 4 AN XY: 135684

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000203

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: 0.00000821 AC: 12 AN: 1461796 Hom.: 0 Cov.: 34 AF XY: 0.00000688 AC XY: 5 AN XY: 727198

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.000157

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: 0.0000166

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000340

ExAC AF: 0.0000330 AC: 4

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Atrial fibrillation, familial, 7 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Aug 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. ClinVar contains an entry for this variant (Variation ID: 573045). This variant has not been reported in the literature in individuals affected with KCNA5-related conditions. This variant is present in population databases (rs767881978, gnomAD 0.02%). This sequence change creates a premature translational stop signal (p.Arg577*) in the KCNA5 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 37 amino acid(s) of the KCNA5 protein. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.43	D
BayesDel_noAF	Pathogenic	0.29
Cadd	Pathogenic	35
Dann	Uncertain	0.99
Eigen	Uncertain	0.27
Eigen_PC	Benign	-0.010
FATHMM_MKL	Benign	0.60	D
MutationTaster	Benign	1.0	D
Vest4		0.59
GERP RS		4.0

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: rs767881978; hg19: chr12-5155042;