chr12-5044182-G-A

Variant names:

• chr12-5044182-G-A
• rs774385439
• NM_002234.4:c.35G>A

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_002234.4(KCNA5):​c.35G>A​(p.Gly12Asp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000144 in 1,384,736 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: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNA5 NM_002234.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.17

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 Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.24928436).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNA5	NM_002234.4	c.35G>A	p.Gly12Asp	missense_variant	Exon 1 of 1	ENST00000252321.5	NP_002225.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNA5	ENST00000252321.5	c.35G>A	p.Gly12Asp	missense_variant	Exon 1 of 1	6	NM_002234.4	ENSP00000252321.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000746 AC: 1 AN: 134006 Hom.: 0 AF XY: 0.0000137 AC XY: 1 AN XY: 73198

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: 0.0000443

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000144 AC: 2 AN: 1384736 Hom.: 0 Cov.: 31 AF XY: 0.00000146 AC XY: 1 AN XY: 683458

Gnomad4 AFR exome AF: 0.00

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000124 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Atrial fibrillation, familial, 7 Uncertain:1

Dec 05, 2020

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine with aspartic acid at codon 12 of the KCNA5 protein (p.Gly12Asp). The glycine residue is weakly conserved and there is a moderate physicochemical difference between glycine and aspartic acid. While this variant is present in population databases (rs774385439), the frequency information is unreliable, as metrics indicate poor data quality at this position in the ExAC database. This variant has not been reported in the literature in individuals with KCNA5-related conditions. 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: "Benign"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
CADD	Benign	20
DANN	Uncertain	1.0
DEOGEN2	Benign	0.27	T
Eigen	Benign	-0.19
Eigen_PC	Benign	-0.0056
FATHMM_MKL	Uncertain	0.90	D
LIST_S2	Benign	0.58	T
M_CAP	Pathogenic	0.61	D
MetaRNN	Benign	0.25	T
MetaSVM	Uncertain	-0.10	T
MutationAssessor	Benign	0.97	L
PrimateAI	Uncertain	0.66	T
PROVEAN	Benign	-0.43	N
REVEL	Benign	0.27
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.0030	D
Polyphen		0.0020	B
Vest4		0.20
MutPred		0.20		Gain of relative solvent accessibility (P = 0.0479);
MVP		1.0
MPC		0.92
ClinPred		0.77	D
GERP RS		4.5
Varity_R		0.24
gMVP		0.60

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: rs774385439; hg19: chr12-5153348;