NM_000217.3:c.-638C>T

Variant names:

• chr12-4910374-C-T
• rs574980784
• NM_000217.3:c.-638C>T

Variant summary

Our verdict is Benign. The variant received -16 ACMG points: 0P and 16B. BP4_Strong BP6_Very_Strong BS1

The NM_000217.3(KCNA1):​c.-638C>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00106 in 152,246 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 Benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0011 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: KCNA1 NM_000217.3 5_prime_UTR
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: -0.00600
• Publications: 0 publications found

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]

KCNA1 Gene-Disease associations (from GenCC):

• episodic ataxia type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, ClinGen, Genomics England PanelApp, Orphanet
• episodic kinesigenic dyskinesia 1

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• genetic developmental and epileptic encephalopathy

  Inheritance: AD, AR Classification: SUPPORTIVE, LIMITED Submitted by: Orphanet, G2P
• isolated autosomal dominant hypomagnesemia, Glaudemans type

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000256654 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -16 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.77).
• BP6: Variant 12-4910374-C-T is Benign according to our data. Variant chr12-4910374-C-T is described in ClinVar as Benign. ClinVar VariationId is 880636.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00106 (161/152246) while in subpopulation AFR AF = 0.0031 (129/41568). AF 95% confidence interval is 0.00267. There are 0 homozygotes in GnomAd4. There are 75 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000217.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNA1	NM_000217.3	MANE Select	c.-638C>T		5_prime_UTR	Exon 1 of 2	NP_000208.2	Q09470

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNA1	ENST00000382545.5	TSL:4 MANE Select	c.-638C>T		5_prime_UTR	Exon 1 of 2	ENSP00000371985.3	Q09470
	ENSG00000256654	ENST00000541095.1	TSL:3	n.7C>T		non_coding_transcript_exon	Exon 1 of 3
	KCNA1	ENST00000543874.3	TSL:2	n.7C>T		non_coding_transcript_exon	Exon 1 of 2

Frequencies

GnomAD3 genomes AF: 0.00106 AC: 162 AN: 152132 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00314

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00111

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: 0.000162

Gnomad OTH AF: 0.00191

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 90 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 76

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 2

East Asian (EAS) AF: 0.00 AC: 0 AN: 4

South Asian (SAS) AF: 0.00 AC: 0 AN: 2

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 2

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 80

Other (OTH) AC: 0 AN: 0

GnomAD4 genome AF: 0.00106 AC: 161 AN: 152246 Hom.: 0 Cov.: 32 AF XY: 0.00101 AC XY: 75 AN XY: 74440

African (AFR) AF: 0.00310 AC: 129 AN: 41568

American (AMR) AF: 0.00111 AC: 17 AN: 15306

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5134

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.000162 AC: 11 AN: 68002

Other (OTH) AF: 0.00189 AC: 4 AN: 2116

Alfa AF: 0.00118 Hom.: 0

Bravo AF: 0.00155

ClinVar

ClinVar submissions

Significance: Benign

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	-	1	Episodic ataxia type 1 (1)
-	-	1	not provided (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.77
CADD	Benign	12
DANN	Benign	0.92
PhyloP100		-0.0060
PromoterAI		-0.066	Neutral

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

Other links and lift over

dbSNP: rs574980784; hg19: chr12-5019540;