11-17779448-G-T

Variant names:

• chr11-17779448-G-T
• rs1353872876
• NM_001112741.2:c.1505-8G>T

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_001112741.2(KCNC1):​c.1505-8G>T variant causes a splice region, intron change. The variant allele was found at a frequency of 0.00000325 in 1,537,988 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000029 (0 hom.)
• Consequence: KCNC1 NM_001112741.2 splice_region, intron
• Scores: Splicing: ADA: 0.1120
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.38
• 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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.31).

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.1505-8G>T		splice_region intron	N/A	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.1505-8G>T		splice_region intron	N/A	ENSP00000265969.7	P48547-2
	KCNC1	ENST00000639325.2	TSL:5	c.1505-8G>T		splice_region intron	N/A	ENSP00000492663.2	A0A1W2PNZ3
	KCNC1	ENST00000640318.2	TSL:5	c.1505-8G>T		splice_region intron	N/A	ENSP00000491189.2	A0A1W2PNZ3

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152174 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: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000693 AC: 1 AN: 144274 AF XY: 0.00

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 FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000179

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000289 AC: 4 AN: 1385814 Hom.: 0 Cov.: 31 AF XY: 0.00000293 AC XY: 2 AN XY: 682974

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 30748

American (AMR) AF: 0.00 AC: 0 AN: 32996

Ashkenazi Jewish (ASJ) AF: 0.0000407 AC: 1 AN: 24576

East Asian (EAS) AF: 0.00 AC: 0 AN: 35274

South Asian (SAS) AF: 0.00 AC: 0 AN: 77678

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48978

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5600

European-Non Finnish (NFE) AF: 0.00000280 AC: 3 AN: 1072690

Other (OTH) AF: 0.00 AC: 0 AN: 57274

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00376316), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152174 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74334

African (AFR) AF: 0.00 AC: 0 AN: 41450

American (AMR) AF: 0.00 AC: 0 AN: 15290

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5176

South Asian (SAS) AF: 0.00 AC: 0 AN: 4828

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10612

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68028

Other (OTH) AF: 0.00 AC: 0 AN: 2094

Alfa AF: 0.0000284 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
CADD	Benign	17
DANN	Benign	0.94
PhyloP100		5.4

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.11
dbscSNV1_RF	Benign	0.26
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: rs1353872876; hg19: chr11-17800995;