rs201701585

Variant names:

• chr20-63407198-T-A
• rs201701585
• NM_172107.4:c.2065A>T

Your query was ambiguous. Multiple possible variants found:

• chr20-63407198-T-A
• chr20-63407198-T-G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_172107.4(KCNQ2):​c.2065A>T​(p.Ile689Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000187 in 1,606,220 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign 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. I689L) has been classified as Benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNQ2 NM_172107.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 1.51
• Publications: 4 publications found

Genes affected

KCNQ2 (HGNC:6296): (potassium voltage-gated channel subfamily Q member 2) The M channel is a slowly activating and deactivating potassium channel that plays a critical role in the regulation of neuronal excitability. The M channel is formed by the association of the protein encoded by this gene and a related protein encoded by the KCNQ3 gene, both integral membrane proteins. M channel currents are inhibited by M1 muscarinic acetylcholine receptors and activated by retigabine, a novel anti-convulsant drug. Defects in this gene are a cause of benign familial neonatal convulsions type 1 (BFNC), also known as epilepsy, benign neonatal type 1 (EBN1). At least five transcript variants encoding five different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

KCNQ2 Gene-Disease associations (from GenCC):

• complex neurodevelopmental disorder

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• developmental and epileptic encephalopathy, 7

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Labcorp Genetics (formerly Invitae), G2P
• neonatal encephalopathy with non-epileptic myoclonus

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• neonatal-onset developmental and epileptic encephalopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• seizures, benign familial neonatal, 1

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• seizures, benign familial neonatal, 2

  Inheritance: AD Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• benign familial infantile epilepsy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• benign familial neonatal-infantile seizures

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• benign neonatal seizures

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• malignant migrating partial seizures of infancy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the KCNQ2 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 319 curated pathogenic missense variants (we use a threshold of 10). The gene has 78 curated benign missense variants. Gene score misZ: 4.0411 (above the threshold of 3.09). Trascript score misZ: 3.6968 (above the threshold of 3.09). GenCC associations: The gene is linked to benign familial infantile epilepsy, malignant migrating partial seizures of infancy, developmental and epileptic encephalopathy, 7, benign familial neonatal-infantile seizures, benign neonatal seizures, neonatal-onset developmental and epileptic encephalopathy, complex neurodevelopmental disorder, seizures, benign familial neonatal, 2, seizures, benign familial neonatal, 1, neonatal encephalopathy with non-epileptic myoclonus.
• BP4: Computational evidence support a benign effect (MetaRNN=0.30870962).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNQ2	NM_172107.4	c.2065A>T	p.Ile689Phe	missense_variant	Exon 17 of 17	ENST00000359125.7	NP_742105.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNQ2	ENST00000359125.7	c.2065A>T	p.Ile689Phe	missense_variant	Exon 17 of 17	1	NM_172107.4	ENSP00000352035.2

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152160 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

GnomAD4 exome AF: 0.00000138 AC: 2 AN: 1454060 Hom.: 0 Cov.: 36 AF XY: 0.00 AC XY: 0 AN XY: 723646

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44624

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26100

East Asian (EAS) AF: 0.00 AC: 0 AN: 39668

South Asian (SAS) AF: 0.00 AC: 0 AN: 86134

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 46486

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111550

Other (OTH) AF: 0.00 AC: 0 AN: 60274

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152160 Hom.: 0 Cov.: 33 AF XY: 0.0000135 AC XY: 1 AN XY: 74342

African (AFR) AF: 0.00 AC: 0 AN: 41456

American (AMR) AF: 0.00 AC: 0 AN: 15288

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5182

South Asian (SAS) AF: 0.00 AC: 0 AN: 4826

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68002

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

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.21
BayesDel_addAF	Uncertain	0.043	T
BayesDel_noAF	Benign	-0.18
CADD	Benign	20
DANN	Benign	0.97
DEOGEN2	Benign	0.35	.;T;T;T;T;D;T;.;.
Eigen	Benign	-0.25
Eigen_PC	Benign	-0.26
FATHMM_MKL	Uncertain	0.80	D
LIST_S2	Uncertain	0.95	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.43	D
MetaRNN	Benign	0.31	T;T;T;T;T;T;T;T;T
MetaSVM	Uncertain	0.53	D
MutationAssessor	Benign	1.6	.;.;.;.;.;L;.;.;.
PhyloP100		1.5
PrimateAI	Benign	0.46	T
PROVEAN	Benign	-1.9	.;.;.;N;.;N;.;N;.
REVEL	Uncertain	0.39
Sift	Uncertain	0.0050	.;.;.;D;.;D;.;D;.
Sift4G	Benign	0.068	T;T;T;T;.;T;T;T;T
Polyphen		0.68	P;.;.;.;.;P;.;P;P
Vest4		0.092
MutPred		0.41		.;.;.;.;.;Gain of sheet (P = 0.0221);.;.;.;
MVP		0.59
MPC		1.0
ClinPred		0.57	D
GERP RS		0.028
Varity_R		0.19
gMVP		0.38
Mutation Taster		=75/25	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: rs201701585; hg19: chr20-62038551;