chr11-17779613-C-A

Variant names:

• chr11-17779613-C-A
• rs578025939
• NM_001112741.2:c.1662C>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PVS1_Moderate PM2

The NM_001112741.2(KCNC1):​c.1662C>A​(p.Tyr554*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. Y554Y) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNC1 NM_001112741.2 stop_gained
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.53
• Publications: 0 publications found

Genes affected

KCNC1 (HGNC:6233): (potassium voltage-gated channel subfamily C member 1) This gene encodes a member of a family of integral membrane proteins that mediate the voltage-dependent potassium ion permeability of excitable membranes. Alternative splicing is thought to result in two transcript variants encoding isoforms that differ at their C-termini. These isoforms have had conflicting names in the literature: the longer isoform has been called both "b" and "alpha", while the shorter isoform has been called both "a" and "beta" (PMIDs 1432046, 12091563). [provided by RefSeq, Oct 2014]

KCNC1 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen, Ambry Genetics
• progressive myoclonic epilepsy type 7

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae), Orphanet
• progressive myoclonus epilepsy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.0546 CDS is truncated, and there are 0 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001112741.2. 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
	KCNC1	NM_001112741.2	MANE Select	c.1662C>A	p.Tyr554*	stop_gained	Exon 3 of 4	NP_001106212.1	P48547-2

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNC1	ENST00000265969.8	TSL:5 MANE Select	c.1662C>A	p.Tyr554*	stop_gained	Exon 3 of 4	ENSP00000265969.7	P48547-2
	KCNC1	ENST00000639325.2	TSL:5	c.1662C>A	p.Tyr554*	stop_gained	Exon 3 of 5	ENSP00000492663.2	A0A1W2PNZ3
	KCNC1	ENST00000640318.2	TSL:5	c.1662C>A	p.Tyr554*	stop_gained	Exon 3 of 5	ENSP00000491189.2	A0A1W2PNZ3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Progressive myoclonic epilepsy type 7 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	41
DANN	Uncertain	1.0
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.84	D
PhyloP100		1.5
Vest4		0.62
GERP RS		4.8
Mutation Taster		=13/187	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs578025939; hg19: chr11-17801160;