17-21703441-C-T

Variant summary

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

The NM_001194958.2(KCNJ18):c.655C>T(p.Arg219Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000381 in 152,418 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.00038 (0 hom., cov: 53)
  • Exomes 𝑓: 0.00046 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: KCNJ18 NM_001194958.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0120

Genes affected

KCNJ18 (HGNC:39080): (potassium inwardly rectifying channel subfamily J member 18) This gene encodes a member of the inwardly rectifying potassium channel family. Transcription of this locus is regulated by thyroid hormone, and the encoded protein plays a role in resting membrane potential maintenance. Mutations in this locus have been associated with thyrotoxic hypokalemic periodic paralysis. [provided by RefSeq, Jan 2013]

ACMG classification

Verdict is Likely_benign. Variant got -4 ACMG points.

• BS2: High AC in GnomAd at 58 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNJ18	NM_001194958.2	c.655C>T	p.Arg219Cys	missense_variant	3/3	ENST00000567955.3
KCNJ18	XM_005276919.4	c.961C>T	p.Arg321Cys	missense_variant	2/2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNJ18	ENST00000567955.3	c.655C>T	p.Arg219Cys	missense_variant	3/3	1	NM_001194958.2	P1

Frequencies

GnomAD3 genomes AF: 0.000381 AC: 58 AN: 152300 Hom.: 0 Cov.: 53

Gnomad AFR AF: 0.0000964

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00144

Gnomad ASJ AF: 0.000288

Gnomad EAS AF: 0.000192

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.0000941

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.000382

Gnomad OTH AF: 0.000955

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.000465 AC: 679 AN: 1460696 Hom.: 0 Cov.: 220 AF XY: 0.000469 AC XY: 341 AN XY: 726664

Gnomad4 AFR exome AF: 0.000418

Gnomad4 AMR exome AF: 0.000962

Gnomad4 ASJ exome AF: 0.000880

Gnomad4 EAS exome AF: 0.000151

Gnomad4 SAS exome AF: 0.000139

Gnomad4 FIN exome AF: 0.0000191

Gnomad4 NFE exome AF: 0.000428

Gnomad4 OTH exome AF: 0.00126

GnomAD4 genome AF: 0.000381 AC: 58 AN: 152418 Hom.: 0 Cov.: 53 AF XY: 0.000429 AC XY: 32 AN XY: 74540

Gnomad4 AFR AF: 0.0000962

Gnomad4 AMR AF: 0.00144

Gnomad4 ASJ AF: 0.000288

Gnomad4 EAS AF: 0.000192

Gnomad4 SAS AF: 0.000207

Gnomad4 FIN AF: 0.0000941

Gnomad4 NFE AF: 0.000382

Gnomad4 OTH AF: 0.000945

ESP6500AA AF: 0.00 AC: 0

ESP6500EA AF: 0.000349 AC: 3

ExAC AF: 0.000346 AC: 42

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Thyrotoxic periodic paralysis, susceptibility to, 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Center For Human Genetics And Laboratory Diagnostics, Dr. Klein, Dr. Rost And Colleagues

Apr 24, 2017

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.50
Cadd	Pathogenic	32
DEOGEN2	Pathogenic	0.88	D
Eigen	Pathogenic	0.73
Eigen_PC	Uncertain	0.59
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Pathogenic	0.99	D
M_CAP	Pathogenic	0.35	D
MetaRNN	Uncertain	0.71	D
MetaSVM	Pathogenic	1.1	D
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-7.7	D
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Vest4		0.57
MVP		0.48
ClinPred		0.78	D
GERP RS		3.2
Varity_R		0.89
gMVP		0.76

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1469374904; hg19: chr17-21319309;