Genetic Variant KCNK18:p.Leu62Ser (chr10-117197673-T-C) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 0P and 4B. BS2

The NM_181840.1(KCNK18):c.185T>C(p.Leu62Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000211 in 1,614,020 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000022 ( 0 hom. )

Consequence

KCNK18
NM_181840.1 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 3.07

Variant links:

Genes affected

KCNK18 (HGNC:19439): (potassium two pore domain channel subfamily K member 18) Potassium channels play a role in many cellular processes including maintenance of the action potential, muscle contraction, hormone secretion, osmotic regulation, and ion flow. This gene encodes a member of the superfamily of potassium channel proteins containing two pore-forming P domains and the encoded protein functions as an outward rectifying potassium channel. A mutation in this gene has been found to be associated with migraine with aura.[provided by RefSeq, Jan 2011]

KCNK18 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

BS2

High AC in GnomAdExome4 at 32 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNK18	NM_181840.1 link	c.185T>C	p.Leu62Ser	missense_variant	Exon 1 of 3	ENST00000334549.1	NP_862823.1	Q7Z418

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNK18	ENST00000334549.1 link	c.185T>C	p.Leu62Ser	missense_variant	Exon 1 of 3	1	NM_181840.1	ENSP00000334650.1		Q7Z418

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152136

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000111

AC:

AN:

251380

Hom.:

AF XY:

0.0000736

AC XY:

AN XY:

135862

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000781

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000219

AC:

AN:

1461884

Hom.:

Cov.:

AF XY:

0.0000165

AC XY:

AN XY:

727244

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000671

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000180

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152136

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74312

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.0000655

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000130

Hom.:

Bravo

AF:

0.0000416

ExAC

AF:

0.0000494

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Jun 30, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.185T>C (p.L62S) alteration is located in exon 1 (coding exon 1) of the KCNK18 gene. This alteration results from a T to C substitution at nucleotide position 185, causing the leucine (L) at amino acid position 62 to be replaced by a serine (S). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Aug 12, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is present in population databases (rs753262034, ExAC 0.04%). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with KCNK18-related conditions. This sequence change replaces leucine with serine at codon 62 of the KCNK18 protein (p.Leu62Ser). The leucine residue is moderately conserved and there is a large physicochemical difference between leucine and serine. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.34

BayesDel_addAF

Benign

-0.25

BayesDel_noAF

Benign

-0.22

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Benign

0.19

Eigen

Benign

0.0027

Eigen_PC

Benign

-0.052

FATHMM_MKL

Benign

0.75

LIST_S2

Benign

0.45

M_CAP

Benign

0.0077

MetaRNN

Uncertain

0.57

MetaSVM

Benign

-1.1

MutationAssessor

Benign

1.8

PrimateAI

Uncertain

0.51

PROVEAN

Benign

-2.1

REVEL

Benign

0.20

Sift

Uncertain

0.0010

Sift4G

Uncertain

0.0040

Polyphen

0.94

Vest4

0.62

MutPred

0.62

Gain of disorder (P = 0.0085);

MVP

0.49

MPC

0.32

ClinPred

0.24

GERP RS

4.3

Varity_R

0.17

gMVP

0.66

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over