12-21765802-C-T

Variant summary

Our verdict is Likely benign. Variant got -4 ACMG points: 1P and 5B. PP2BP4BS2

The NM_004982.4(KCNJ8):​c.1196G>A​(p.Arg399Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000744 in 1,613,898 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 0.000020 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000062 ( 0 hom. )

Consequence

KCNJ8
NM_004982.4 missense

Scores

2
5
12

Clinical Significance

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

Conservation

PhyloP100: 5.54
Variant links:
Genes affected
KCNJ8 (HGNC:6269): (potassium inwardly rectifying channel subfamily J member 8) Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier type potassium channel. The encoded protein, which has a greater tendency to allow potassium to flow into a cell rather than out of a cell, is controlled by G-proteins. Defects in this gene may be a cause of J-wave syndromes and sudden infant death syndrome (SIDS). [provided by RefSeq, May 2012]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -4 ACMG points.

PP2
Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCNJ8. . Gene score misZ 3.4549 (greater than the threshold 3.09). Trascript score misZ 4.3809 (greater than threshold 3.09). GenCC has associacion of gene with hypertrichotic osteochondrodysplasia Cantu type, Brugada syndrome, Brugada syndrome 1.
BP4
Computational evidence support a benign effect (MetaRNN=0.27668092).
BS2
High AC in GnomAdExome4 at 9 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
KCNJ8NM_004982.4 linkuse as main transcriptc.1196G>A p.Arg399Gln missense_variant 3/3 ENST00000240662.3 NP_004973.1
LOC105369689XR_007063241.1 linkuse as main transcriptn.631+5717C>T intron_variant, non_coding_transcript_variant

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
KCNJ8ENST00000240662.3 linkuse as main transcriptc.1196G>A p.Arg399Gln missense_variant 3/31 NM_004982.4 ENSP00000240662 P1
ENST00000542489.1 linkuse as main transcriptn.107-554C>T intron_variant, non_coding_transcript_variant 3

Frequencies

GnomAD3 genomes
AF:
0.0000197
AC:
3
AN:
152152
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
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
GnomAD3 exomes
AF:
0.00000795
AC:
2
AN:
251454
Hom.:
0
AF XY:
0.00000736
AC XY:
1
AN XY:
135898
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.00
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:
0.00
Gnomad OTH exome
AF:
0.000163
GnomAD4 exome
AF:
0.00000616
AC:
9
AN:
1461746
Hom.:
0
Cov.:
31
AF XY:
0.00000275
AC XY:
2
AN XY:
727196
show subpopulations
Gnomad4 AFR exome
AF:
0.0000597
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.0000232
Gnomad4 FIN exome
AF:
0.0000562
Gnomad4 NFE exome
AF:
0.00000180
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.0000197
AC:
3
AN:
152152
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74312
show subpopulations
Gnomad4 AFR
AF:
0.0000483
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000658
Hom.:
0
Bravo
AF:
0.0000189
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Brugada syndrome Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpDec 03, 2023This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 399 of the KCNJ8 protein (p.Arg399Gln). This variant is present in population databases (rs142014286, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with KCNJ8-related conditions. ClinVar contains an entry for this variant (Variation ID: 1480643). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt KCNJ8 protein function with a negative predictive value of 95%. 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. -
Cardiovascular phenotype Uncertain:1
Uncertain significance, criteria provided, single submitterclinical testingAmbry GeneticsDec 08, 2023The p.R399Q variant (also known as c.1196G>A), located in coding exon 2 of the KCNJ8 gene, results from a G to A substitution at nucleotide position 1196. The arginine at codon 399 is replaced by glutamine, an amino acid with highly similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.17
BayesDel_addAF
Benign
-0.12
T
BayesDel_noAF
Benign
-0.22
CADD
Pathogenic
27
DANN
Pathogenic
1.0
DEOGEN2
Benign
0.25
T
Eigen
Benign
0.12
Eigen_PC
Uncertain
0.29
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.89
D
M_CAP
Benign
0.016
T
MetaRNN
Benign
0.28
T
MetaSVM
Benign
-0.72
T
MutationAssessor
Benign
0.0
N
MutationTaster
Benign
1.0
D;D
PrimateAI
Uncertain
0.50
T
PROVEAN
Benign
-0.10
N
REVEL
Uncertain
0.41
Sift
Uncertain
0.018
D
Sift4G
Benign
0.37
T
Polyphen
0.80
P
Vest4
0.42
MVP
0.78
MPC
1.4
ClinPred
0.26
T
GERP RS
5.9
Varity_R
0.12
gMVP
0.73

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.

Other links and lift over

dbSNP: rs142014286; hg19: chr12-21918736; COSMIC: COSV53717043; API