rs796052604

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM2PP2PP3_ModeratePP5

The NM_002241.5(KCNJ10):​c.221C>T​(p.Thr74Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,220 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. T74T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

KCNJ10
NM_002241.5 missense

Scores

12
5
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:1

Conservation

PhyloP100: 10.0

Publications

0 publications found
Variant links:
Genes affected
KCNJ10 (HGNC:6256): (potassium inwardly rectifying channel subfamily J member 10) This gene encodes a member of the inward rectifier-type potassium channel family, characterized by having a greater tendency to allow potassium to flow into, rather than out of, a cell. The encoded protein may form a heterodimer with another potassium channel protein and may be responsible for the potassium buffering action of glial cells in the brain. Mutations in this gene have been associated with seizure susceptibility of common idiopathic generalized epilepsy syndromes. [provided by RefSeq, Jul 2008]
KCNJ10 Gene-Disease associations (from GenCC):
  • EAST syndrome
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Ambry Genetics, PanelApp Australia, G2P, Labcorp Genetics (formerly Invitae), ClinGen
  • Pendred syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • enlarged vestibular aqueduct syndrome
    Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 7 uncertain in NM_002241.5
PM2
Very rare variant in population databases, with high coverage;
PP2
Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 14 curated pathogenic missense variants (we use a threshold of 10). The gene has 1 curated benign missense variants. Trascript score misZ: 2.7053 (below the threshold of 3.09). GenCC associations: The gene is linked to EAST syndrome, enlarged vestibular aqueduct syndrome, Pendred syndrome.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.908
PP5
Variant 1-160042312-G-A is Pathogenic according to our data. Variant chr1-160042312-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 205818.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
KCNJ10NM_002241.5 linkc.221C>T p.Thr74Ile missense_variant Exon 2 of 2 ENST00000644903.1 NP_002232.2 P78508

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
KCNJ10ENST00000644903.1 linkc.221C>T p.Thr74Ile missense_variant Exon 2 of 2 NM_002241.5 ENSP00000495557.1 P78508

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152220
Hom.:
0
Cov.:
32
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:
0.00
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
Cov.:
32
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152220
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74360
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41456
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68030
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Apr 15, 2014
GeneDx
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

p.Thr74Ile (ACC>ATC): c.221 C>T in exon 2 of the KCNJ10 gene (NM_002241.4). The T74I variant has not been published as a mutation, nor has it been reported as a benign polymorphism to our knowledge. It was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The T74I variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved in mammals in the M1 transmembrane domain of the KCNJ10 protein and missense mutations in nearby residues (V84M, G77R, F75L) have been reported in association with epilepsy, supporting the functional importance of this region of the KCNJ10 protein. In addition, in silico analysis predicts this variant is probably damaging to the protein structure/function. Therefore, this variant is a strong candidate for a pathogenic mutation, however the possibility that it is a benign variant cannot be excluded. The variant is found in EPILEPSY panel(s). -

EAST syndrome Uncertain:1
Feb 22, 2020
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant has not been reported in the literature in individuals with KCNJ10-related disease. ClinVar contains an entry for this variant (Variation ID: 205818). This sequence change replaces threonine with isoleucine at codon 74 of the KCNJ10 protein (p.Thr74Ile). The threonine residue is highly conserved and there is a moderate physicochemical difference between threonine and isoleucine. This variant is not present in population databases (ExAC no frequency). Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C15"). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.70
BayesDel_addAF
Pathogenic
0.36
D
BayesDel_noAF
Pathogenic
0.29
CADD
Pathogenic
32
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.84
.;.;D;D;.;D;D
Eigen
Pathogenic
0.80
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.91
D;D;.;.;D;.;D
M_CAP
Pathogenic
0.34
D
MetaRNN
Pathogenic
0.91
D;D;D;D;D;D;D
MetaSVM
Pathogenic
0.90
D
MutationAssessor
Uncertain
2.8
.;.;M;M;.;M;M
PhyloP100
10
PrimateAI
Pathogenic
0.84
D
PROVEAN
Benign
-2.1
.;.;.;N;.;.;.
REVEL
Pathogenic
0.81
Sift
Uncertain
0.0020
.;.;.;D;.;.;.
Sift4G
Uncertain
0.012
.;.;.;D;.;.;.
Polyphen
1.0
.;.;D;D;.;D;D
Vest4
0.49
MutPred
0.73
Loss of glycosylation at T74 (P = 0.0921);Loss of glycosylation at T74 (P = 0.0921);Loss of glycosylation at T74 (P = 0.0921);Loss of glycosylation at T74 (P = 0.0921);.;Loss of glycosylation at T74 (P = 0.0921);Loss of glycosylation at T74 (P = 0.0921);
MVP
0.83
MPC
1.5
ClinPred
0.99
D
GERP RS
4.2
PromoterAI
-0.021
Neutral
Varity_R
0.51
gMVP
0.95
Mutation Taster
=32/68
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs796052604; hg19: chr1-160012102; COSMIC: COSV63633191; COSMIC: COSV63633191; API