rs753575587

Variant names:

• chr20-49373551-C-A
• rs753575587
• NM_004975.4:c.2009G>T

Your query was ambiguous. Multiple possible variants found:

• chr20-49373551-C-A
• chr20-49373551-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP3

The ENST00000371741.6(KCNB1):​c.2009G>T​(p.Arg670Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000658 in 152,040 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R670Q) has been classified as Likely benign.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: KCNB1 ENST00000371741.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.84
• Publications: 1 publications found

Genes affected

KCNB1 (HGNC:6231): (potassium voltage-gated channel subfamily B member 1) Voltage-gated potassium (Kv) channels represent the most complex class of voltage-gated ion channels from both functional and structural standpoints. Their diverse functions include regulating neurotransmitter release, heart rate, insulin secretion, neuronal excitability, epithelial electrolyte transport, smooth muscle contraction, and cell volume. Four sequence-related potassium channel genes - shaker, shaw, shab, and shal - have been identified in Drosophila, and each has been shown to have human homolog(s). This gene encodes a member of the potassium channel, voltage-gated, shab-related subfamily. This member is a delayed rectifier potassium channel and its activity is modulated by some other family members. [provided by RefSeq, Jul 2008]

KCNB1 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy, 26

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
• undetermined early-onset epileptic encephalopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000290421 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.826

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000371741.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNB1	NM_004975.4	MANE Select	c.2009G>T	p.Arg670Leu	missense	Exon 2 of 2	NP_004966.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNB1	ENST00000371741.6	TSL:1 MANE Select	c.2009G>T	p.Arg670Leu	missense	Exon 2 of 2	ENSP00000360806.3
	KCNB1	ENST00000635465.1	TSL:1	c.2009G>T	p.Arg670Leu	missense	Exon 3 of 3	ENSP00000489193.1
	KCNB1	ENST00000635878.1	TSL:5	c.97-74168G>T		intron	N/A	ENSP00000489908.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152040 Hom.: 0 Cov.: 32

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: 0.0000943

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 152040 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74262

African (AFR) AF: 0.00 AC: 0 AN: 41394

American (AMR) AF: 0.00 AC: 0 AN: 15258

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3464

East Asian (EAS) AF: 0.00 AC: 0 AN: 5186

South Asian (SAS) AF: 0.00 AC: 0 AN: 4810

European-Finnish (FIN) AF: 0.0000943 AC: 1 AN: 10608

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68004

Other (OTH) AF: 0.00 AC: 0 AN: 2088

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.27
BayesDel_addAF	Uncertain	0.026	T
BayesDel_noAF	Benign	-0.20
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Benign	0.38	T
Eigen	Pathogenic	0.76
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	D
M_CAP	Benign	0.043	D
MetaRNN	Pathogenic	0.83	D
MetaSVM	Benign	-0.83	T
MutationAssessor	Uncertain	2.4	M
PhyloP100		5.8
PrimateAI	Uncertain	0.50	T
PROVEAN	Uncertain	-2.5	N
REVEL	Uncertain	0.35
Sift	Uncertain	0.0020	D
Sift4G	Uncertain	0.0090	D
Polyphen		0.99	D
Vest4		0.57
MutPred		0.78		Loss of MoRF binding (P = 0.0311)
MVP		0.53
MPC		0.25
ClinPred		0.95	D
GERP RS		5.7
Varity_R		0.30
gMVP		0.51
Mutation Taster		=91/9	polymorphism

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: rs753575587; hg19: chr20-47990088; COSMIC: COSV100870420; COSMIC: COSV100870420;