12-5044239-G-C

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 0P and 6B. BP4_Moderate BS2

The NM_002234.4(KCNA5):c.92G>C(p.Gly31Ala) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000175 in 1,539,072 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign 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. G31V) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000019 (0 hom.)
• Consequence: KCNA5 NM_002234.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.437

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 -6 ACMG points.

• BP4: Computational evidence support a benign effect (MetaRNN=0.0719409).
• BS2: High AC in GnomAdExome at 5 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNA5	NM_002234.4	c.92G>C	p.Gly31Ala	missense_variant	1/1	ENST00000252321.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNA5	ENST00000252321.5	c.92G>C	p.Gly31Ala	missense_variant	1/1		NM_002234.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152228 Hom.: 0 Cov.: 33

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: 0.000207

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000369 AC: 5 AN: 135632 Hom.: 0 AF XY: 0.0000540 AC XY: 4 AN XY: 74108

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: 0.0000882

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000587

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000187 AC: 26 AN: 1386844 Hom.: 0 Cov.: 31 AF XY: 0.0000234 AC XY: 16 AN XY: 684660

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: 0.000114

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000148

Gnomad4 OTH exome AF: 0.0000173

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152228 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 74366

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000756

ExAC AF: 0.0000204 AC: 2

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

GeneDx

Dec 13, 2018

Has not been previously reported as pathogenic or benign to our knowledge; Observed in 0.0038% (5/130216) of global alleles in large population cohorts (Lek et al., 2016); Identified in other individuals referred for arrhythmia genetic testing at GeneDx, although at least one of these probands harbored an additional cardiogenetic variant that likely contributed to the phenotype; In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.058
BayesDel_addAF	Benign	-0.20	T
BayesDel_noAF	Benign	-0.32
Cadd	Benign	9.1
Dann	Benign	0.78
DEOGEN2	Benign	0.19	T
Eigen	Benign	-1.0
Eigen_PC	Benign	-0.98
FATHMM_MKL	Benign	0.11	N
LIST_S2	Benign	0.44	T
M_CAP	Pathogenic	0.45	D
MetaRNN	Benign	0.072	T
MetaSVM	Uncertain	-0.073	T
MutationAssessor	Benign	0.0	N
MutationTaster	Benign	1.0	N
PrimateAI	Uncertain	0.52	T
PROVEAN	Benign	0.050	N
REVEL	Benign	0.27
Sift	Benign	0.62	T
Sift4G	Benign	0.71	T
Polyphen		0.0010	B
Vest4		0.057
MutPred		0.083		Gain of relative solvent accessibility (P = 0.1684);
MVP		1.0
MPC		0.57
ClinPred		0.025	T
GERP RS		-0.27
Varity_R		0.093
gMVP		0.35

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: rs61737395; hg19: chr12-5153405;