8-139618328-C-A

Position:

• chr8-139618328-C-A

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 1P and 4B. PP2 BS2

The NM_001282534.2(KCNK9):​c.1055G>T​(p.Ser352Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000137 in 1,461,892 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000014 (0 hom.)
• Consequence: KCNK9 NM_001282534.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.31

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]

KCNK9 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• 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.
• BS2: High AC in GnomAdExome4 at 20 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNK9	NM_001282534.2	c.1055G>T	p.Ser352Ile	missense_variant	2/2	ENST00000520439.3	NP_001269463.1
KCNK9	NR_104210.2	n.1186G>T		non_coding_transcript_exon_variant	2/4

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNK9	ENST00000520439.3	c.1055G>T	p.Ser352Ile	missense_variant	2/2	1	NM_001282534.2	ENSP00000430676.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251476 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135912

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: 0.00

GnomAD4 exome AF: 0.0000137 AC: 20 AN: 1461892 Hom.: 0 Cov.: 29 AF XY: 0.0000179 AC XY: 13 AN XY: 727248

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000171

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

TwinsUK AF: 0.00 AC: 0

ALSPAC AF: 0.000519 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Birk-Barel syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Feb 02, 2022

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as VUS-3B. Following criteria are met: 0104 - Dominant negative is a known mechanism of disease in this gene and is associated with Birk-Barel syndrome MIM#612292. (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0113 - This gene is known to be imprinted. The paternal allele is silenced (PMID: 27151206). (I) 0200 - Variant is predicted to result in a missense amino acid change from serine to isoleucine. (I) 0251 - This variant is heterozygous. (I) 0302 - Variant is present in gnomAD <0.001 for a dominant condition (v2: 1 heterozygote, 0 homozygotes). (SP) 0309 - An alternative amino acid change at the same position has been observed in gnomAD (v2: 1 heterozygote, 0 homozygote). (I) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0807 - This variant has no previous evidence of pathogenicity. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.23
BayesDel_addAF	Benign	-0.062	T
BayesDel_noAF	Benign	-0.15
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.60	D;D;D;D;.
Eigen	Pathogenic	0.73
Eigen_PC	Pathogenic	0.68
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.90	.;D;.;.;D
M_CAP	Benign	0.032	D
MetaRNN	Uncertain	0.55	D;D;D;D;D
MetaSVM	Benign	-0.82	T
MutationAssessor	Uncertain	2.4	M;M;M;M;.
PrimateAI	Benign	0.45	T
PROVEAN	Uncertain	-3.5	.;D;D;.;.
REVEL	Uncertain	0.37
Sift	Uncertain	0.0020	.;D;D;.;.
Sift4G	Uncertain	0.0020	.;D;D;.;.
Polyphen		1.0	D;D;D;D;.
Vest4		0.47, 0.43
MutPred		0.43		Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);Gain of sheet (P = 0.0149);.;
MVP		0.84
MPC		2.4
ClinPred		0.97	D
GERP RS		5.5
Varity_R		0.73
gMVP		0.81

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: rs774633097; hg19: chr8-140630571;