rs104894352

chr12-4912601-T-Achr12-4912601-T-C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_000217.3(KCNA1):c.1223T>A(p.Val408Glu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/20 in silico tools predict a damaging outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V408A) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 30)
• Consequence: KCNA1 NM_000217.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 8.02

Genes affected

KCNA1 (HGNC:6218): (potassium voltage-gated channel subfamily A member 1) This gene encodes a voltage-gated delayed potassium channel that is phylogenetically related to the Drosophila Shaker channel. The encoded protein has six putative transmembrane segments (S1-S6), and the loop between S5 and S6 forms the pore and contains the conserved selectivity filter motif (GYGD). The functional channel is a homotetramer. The N-terminus of the channel is associated with beta subunits that can modify the inactivation properties of the channel as well as affect expression levels. The C-terminus of the channel is complexed to a PDZ domain protein that is responsible for channel targeting. Mutations in this gene have been associated with myokymia with periodic ataxia (AEMK). [provided by RefSeq, Jul 2008]

(HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_000217.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr12-4912601-T-C is described in ClinVar as [Pathogenic]. Clinvar id is 13480.Status of the report is no_assertion_criteria_provided, 0 stars.
• PP2: Missense variant where missense usually causes diseases, KCNA1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.955

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNA1	NM_000217.3	c.1223T>A	p.Val408Glu	missense_variant	2/2	ENST00000382545.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNA1	ENST00000382545.5	c.1223T>A	p.Val408Glu	missense_variant	2/2	4	NM_000217.3	P1
	ENST00000640877.1	n.606+2129T>A		intron_variant, non_coding_transcript_variant		5

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome Cov.: 43

GnomAD4 genome Cov.: 30

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
Cadd	Pathogenic	32
Dann	Uncertain	0.99
DEOGEN2	Pathogenic	0.99	D
Eigen	Pathogenic	0.87
Eigen_PC	Pathogenic	0.80
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.98	D
M_CAP	Pathogenic	0.73	D
MetaRNN	Pathogenic	0.95	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.5	H
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.92	D
PROVEAN	Pathogenic	-5.3	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.94
MutPred		0.75		Gain of catalytic residue at S409 (P = 0.0229);
MVP		0.99
MPC		3.0
ClinPred		1.0	D
GERP RS		4.9
Varity_R		0.97
gMVP		1.0

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: rs104894352; hg19: chr12-5021767;