chr11-128839644-G-T

Variant names:

• chr11-128839644-G-T
• rs104894245
• NM_153766.3:c.600C>A

Variant summary

Our verdict is Pathogenic. The variant received 15 ACMG points: 15P and 0B. PS1 PM1 PM2 PP2 PP3_Strong PP5_Moderate

The NM_153766.3(KCNJ1):​c.600C>A​(p.Ser200Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,420 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 Likely pathogenic (★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Pathogenic in ClinVar.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNJ1 NM_153766.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 0.526
• Publications: 0 publications found

Genes affected

KCNJ1 (HGNC:6255): (potassium inwardly rectifying channel subfamily J member 1) 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. It is activated by internal ATP and probably plays an important role in potassium homeostasis. The encoded protein has a greater tendency to allow potassium to flow into a cell rather than out of a cell. Mutations in this gene have been associated with antenatal Bartter syndrome, which is characterized by salt wasting, hypokalemic alkalosis, hypercalciuria, and low blood pressure. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

KCNJ1 Gene-Disease associations (from GenCC):

• Bartter disease type 2

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• antenatal Bartter syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Pathogenic. The variant received 15 ACMG points.

• PS1: Transcript NM_153766.3 (KCNJ1) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar.
• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_153766.3
• 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 23 curated pathogenic missense variants (we use a threshold of 10). The gene has 3 curated benign missense variants. Gene score misZ: -0.27693 (below the threshold of 3.09). Trascript score misZ: 0.38698 (below the threshold of 3.09). GenCC associations: The gene is linked to antenatal Bartter syndrome, Bartter disease type 2.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.963
• PP5: Variant 11-128839644-G-T is Pathogenic according to our data. Variant chr11-128839644-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1995667.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNJ1	NM_153766.3	c.600C>A	p.Ser200Arg	missense_variant	Exon 3 of 3	ENST00000392666.6	NP_722450.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNJ1	ENST00000392666.6	c.600C>A	p.Ser200Arg	missense_variant	Exon 3 of 3	1	NM_153766.3	ENSP00000376434.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461420 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727000

African (AFR) AF: 0.00 AC: 0 AN: 33478

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52964

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112002

Other (OTH) AF: 0.00 AC: 0 AN: 60390

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Pathogenic:1

May 17, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). A different variant (c.657C>G ) giving rise to the same protein effect has been determined to be pathogenic (PMID: 8841184, 24400161, 29942493). This suggests that this variant is also likely to be causative of disease. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces serine, which is neutral and polar, with arginine, which is basic and polar, at codon 219 of the KCNJ1 protein (p.Ser219Arg). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.40
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	.;.;.;.;D
Eigen	Uncertain	0.43
Eigen_PC	Uncertain	0.38
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.92	.;D;.;.;D
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.96	D;D;D;D;D
MetaSVM	Pathogenic	0.89	D
MutationAssessor	Uncertain	2.5	.;.;.;.;M
PhyloP100		0.53
PrimateAI	Uncertain	0.73	T
PROVEAN	Uncertain	-4.3	D;D;D;D;D
REVEL	Pathogenic	0.87
Sift	Pathogenic	0.0	D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D
Polyphen		1.0	.;.;.;.;D
Vest4		0.63
MutPred		0.96		.;.;.;.;Gain of MoRF binding (P = 0.0241);
MVP		0.90
MPC		0.27
ClinPred		0.99	D
GERP RS		3.9
Varity_R		0.92
gMVP		0.86
Mutation Taster		=1/99	disease causing

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

Other links and lift over

dbSNP: rs104894245; hg19: chr11-128709539;