8-139618406-T-C

Position:

• chr8-139618406-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM2 PP2 BP4_Moderate

The NM_001282534.2(KCNK9):​c.977A>G​(p.Tyr326Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. Y326Y) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: KCNK9 NM_001282534.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 1.68

Genes affected

KCNK9 (HGNC:6283): (potassium two pore domain channel subfamily K member 9) This gene encodes a protein that contains multiple transmembrane regions and two pore-forming P domains and functions as a pH-dependent potassium channel. Amplification and overexpression of this gene have been observed in several types of human carcinomas. This gene is imprinted in the brain, with preferential expression from the maternal allele. A mutation in this gene was associated with Birk-Barel dysmorphism syndrome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2017]

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), KCNK9. . Gene score misZ 2.9038 (greater than the threshold 3.09). Trascript score misZ 3.4593 (greater than threshold 3.09). GenCC has associacion of gene with Birk-Barel syndrome.
• BP4: Computational evidence support a benign effect (MetaRNN=0.24105105).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
KCNK9	NM_001282534.2	c.977A>G	p.Tyr326Cys	missense_variant	2/2	ENST00000520439.3
KCNK9	NR_104210.2	n.1108A>G		non_coding_transcript_exon_variant	2/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
KCNK9	ENST00000520439.3	c.977A>G	p.Tyr326Cys	missense_variant	2/2	1	NM_001282534.2	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461888 Hom.: 0 Cov.: 29 AF XY: 0.00000138 AC XY: 1 AN XY: 727242

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

EpiCase AF: 0.0000545

EpiControl AF: 0.00

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

GeneDx

Dec 12, 2022

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.56
CADD	Benign	16
DANN	Benign	0.93
DEOGEN2	Uncertain	0.51	D;D;D;D;.
Eigen	Benign	-0.37
Eigen_PC	Benign	-0.46
FATHMM_MKL	Uncertain	0.81	D
LIST_S2	Uncertain	0.86	.;D;.;.;D
M_CAP	Benign	0.0053	T
MetaRNN	Benign	0.24	T;T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.6	L;L;L;L;.
MutationTaster	Benign	0.99	N;N;N
PrimateAI	Benign	0.45	T
PROVEAN	Uncertain	-2.7	.;D;D;.;.
REVEL	Benign	0.13
Sift	Benign	0.070	.;T;T;.;.
Sift4G	Benign	0.066	.;T;T;.;.
Polyphen		0.95	P;P;P;P;.
Vest4		0.58, 0.52
MutPred		0.29		Loss of loop (P = 0.0986);Loss of loop (P = 0.0986);Loss of loop (P = 0.0986);Loss of loop (P = 0.0986);.;
MVP		0.54
MPC		2.2
ClinPred		0.61	D
GERP RS		2.2
Varity_R		0.11
gMVP		0.69

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr8-140630649;