21-37625218-C-T

Variant summary

Our verdict is Likely benign. Variant got -5 ACMG points: 1P and 6B. PP2 BP4_Moderate BS2

The NM_002240.5(KCNJ6):c.1213G>A(p.Glu405Lys) variant causes a missense change. The variant allele was found at a frequency of 0.0000304 in 1,614,070 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 11/18 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000039 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000029 (1 hom.)
• Consequence: KCNJ6 NM_002240.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.78

Genes affected

KCNJ6 (HGNC:6267): (potassium inwardly rectifying channel subfamily J member 6) This gene encodes a member of the G protein-coupled inwardly-rectifying potassium channel family of inward rectifier potassium channels. This type of potassium channel allows a greater flow of potassium into the cell than out of it. These proteins modulate many physiological processes, including heart rate in cardiac cells and circuit activity in neuronal cells, through G-protein coupled receptor stimulation. Mutations in this gene are associated with Keppen-Lubinsky Syndrome, a rare condition characterized by severe developmental delay, facial dysmorphism, and intellectual disability. [provided by RefSeq, Apr 2015]

(HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -5 ACMG points.

• PP2: Missense variant where missense usually causes diseases, KCNJ6
• BP4: Computational evidence support a benign effect (MetaRNN=0.1777291).
• BS2: High AC in GnomAd at 6 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNJ6	NM_002240.5	c.1213G>A	p.Glu405Lys	missense_variant	4/4	ENST00000609713.2
KCNJ6-AS1	NR_183540.1	n.408-73337C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNJ6	ENST00000609713.2	c.1213G>A	p.Glu405Lys	missense_variant	4/4	1	NM_002240.5	P1
	ENST00000667151.1	n.161-21329C>T		intron_variant, non_coding_transcript_variant
KCNJ6	ENST00000645093.1	c.1213G>A	p.Glu405Lys	missense_variant	5/5			P1

Frequencies

GnomAD3 genomes AF: 0.0000394 AC: 6 AN: 152186 Hom.: 0 Cov.: 33

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: 0.0000942

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000566 AC: 14 AN: 247502 Hom.: 0 AF XY: 0.0000595 AC XY: 8 AN XY: 134462

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.000167

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.000186

Gnomad NFE exome AF: 0.0000629

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000294 AC: 43 AN: 1461884 Hom.: 1 Cov.: 30 AF XY: 0.0000193 AC XY: 14 AN XY: 727244

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000447

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.000101

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.000243

Gnomad4 NFE exome AF: 0.0000180

Gnomad4 OTH exome AF: 0.0000331

GnomAD4 genome AF: 0.0000394 AC: 6 AN: 152186 Hom.: 0 Cov.: 33 AF XY: 0.0000538 AC XY: 4 AN XY: 74344

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: 0.0000942

Gnomad4 NFE AF: 0.0000588

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000386 Hom.: 0

Bravo AF: 0.0000302

ExAC AF: 0.0000414 AC: 5

EpiCase AF: 0.00

EpiControl AF: 0.000119

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 13, 2023

This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 405 of the KCNJ6 protein (p.Glu405Lys). This variant is present in population databases (rs758545337, gnomAD 0.02%). This variant has not been reported in the literature in individuals affected with KCNJ6-related conditions. ClinVar contains an entry for this variant (Variation ID: 1365568). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. 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	Benign	0.070
BayesDel_addAF	Benign	-0.19	T
BayesDel_noAF	Benign	-0.24
Cadd	Benign	21
Dann	Benign	0.87
DEOGEN2	Benign	0.41	T;T
Eigen	Benign	-0.20
Eigen_PC	Benign	-0.0066
FATHMM_MKL	Uncertain	0.92	D
M_CAP	Benign	0.016	T
MetaRNN	Benign	0.18	T;T
MetaSVM	Benign	-0.29	T
MutationAssessor	Benign	0.69	N;N
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.50	T
Sift4G	Benign	0.33	T;.
Polyphen		0.088	B;B
Vest4		0.34
MutPred		0.26		Gain of ubiquitination at E405 (P = 0.0045);Gain of ubiquitination at E405 (P = 0.0045);
MVP		0.15
MPC		1.3
ClinPred		0.31	T
GERP RS		5.8
Varity_R		0.23
gMVP		0.44

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

Other links and lift over

dbSNP: rs758545337; hg19: chr21-38997520;