Genetic Variant KCNK18:p.Thr112Met (chr10-117201270-C-T) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 0P and 2B. BP4BS2_Supporting

The NM_181840.1(KCNK18):c.335C>T(p.Thr112Met) variant causes a missense change. The variant allele was found at a frequency of 0.0000415 in 1,613,692 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000042 ( 0 hom. )

Consequence

KCNK18
NM_181840.1 missense

Scores

Clinical Significance

Uncertain significance criteria provided, single submitter U:1

Conservation

PhyloP100: 4.09

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 -2 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.4211284).

BS2

High AC in GnomAd4 at 5 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNK18	NM_181840.1 link	c.335C>T	p.Thr112Met	missense_variant	Exon 2 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.335C>T	p.Thr112Met	missense_variant	Exon 2 of 3	1	NM_181840.1	ENSP00000334650.1		Q7Z418

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152140

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000193

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.000189

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000677

AC:

AN:

251140

Hom.:

AF XY:

0.0000884

AC XY:

AN XY:

135746

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000867

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000935

Gnomad NFE exome

AF:

0.0000792

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000424

AC:

AN:

1461434

Hom.:

Cov.:

AF XY:

0.0000413

AC XY:

AN XY:

727036

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.0000894

Gnomad4 ASJ exome

AF:

0.0000383

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.0000941

Gnomad4 NFE exome

AF:

0.0000432

Gnomad4 OTH exome

AF:

0.0000331

GnomAD4 genome

AF:

0.0000328

AC:

AN:

152258

Hom.:

Cov.:

AF XY:

0.0000269

AC XY:

AN XY:

74444

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000193

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.000189

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000412

Hom.:

Bravo

AF:

0.0000264

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ExAC

AF:

0.0000906

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

not specified

Uncertain:1

Apr 23, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.335C>T (p.T112M) alteration is located in exon 2 (coding exon 2) of the KCNK18 gene. This alteration results from a C to T substitution at nucleotide position 335, causing the threonine (T) at amino acid position 112 to be replaced by a methionine (M). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.26

BayesDel_addAF

Uncertain

0.060

BayesDel_noAF

Uncertain

0.050

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.87

Eigen

Pathogenic

0.75

Eigen_PC

Pathogenic

0.68

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Benign

0.85

M_CAP

Benign

0.020

MetaRNN

Benign

0.42

MetaSVM

Benign

-0.54

MutationAssessor

Pathogenic

3.1

PrimateAI

Uncertain

0.52

PROVEAN

Pathogenic

-5.1

REVEL

Uncertain

0.35

Sift

Uncertain

0.026

Sift4G

Uncertain

0.0090

Polyphen

1.0

Vest4

0.40

MVP

0.60

MPC

0.27

ClinPred

0.94

GERP RS

4.3

Varity_R

0.41

gMVP

0.87

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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