11-17736494-G-T

Variant names:

• chr11-17736494-G-T
• NM_001112741.2:c.492G>T
• KCNC1 p.Arg164Arg

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_001112741.2(KCNC1):​c.492G>T​(p.Arg164Arg) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Synonymous variant affecting the same amino acid position (i.e. R164R) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: KCNC1 NM_001112741.2 synonymous
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.50
• 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: Ambry Genetics, ClinGen
• progressive myoclonic epilepsy type 7

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

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.57).
• BP7: Synonymous conserved (PhyloP=1.5 with no splicing effect.

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.492G>T	p.Arg164Arg	synonymous	Exon 1 of 4	NP_001106212.1	P48547-2
	KCNC1	NM_004976.4		c.492G>T	p.Arg164Arg	synonymous	Exon 1 of 2	NP_004967.1	P48547-1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNC1	ENST00000265969.8	TSL:5 MANE Select	c.492G>T	p.Arg164Arg	synonymous	Exon 1 of 4	ENSP00000265969.7	P48547-2
	KCNC1	ENST00000379472.4	TSL:1	c.492G>T	p.Arg164Arg	synonymous	Exon 1 of 2	ENSP00000368785.3	P48547-1
	KCNC1	ENST00000639325.2	TSL:5	c.492G>T	p.Arg164Arg	synonymous	Exon 1 of 5	ENSP00000492663.2	A0A1W2PNZ3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1441330 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 716836

African (AFR) AF: 0.00 AC: 0 AN: 33078

American (AMR) AF: 0.00 AC: 0 AN: 43230

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25832

East Asian (EAS) AF: 0.00 AC: 0 AN: 39232

South Asian (SAS) AF: 0.00 AC: 0 AN: 84904

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 42324

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5694

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1107292

Other (OTH) AF: 0.00 AC: 0 AN: 59744

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.57
CADD	Benign	9.3
DANN	Benign	0.75
PhyloP100		1.5

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Other links and lift over

hg19: chr11-17758041;