11-17388056-G-T

Variant names:

• chr11-17388056-G-T
• rs104894236
• NM_000525.4:c.36C>A

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PVS1 PM2 PP5

The NM_000525.4(KCNJ11):​c.36C>A​(p.Tyr12*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: KCNJ11 NM_000525.4 stop_gained
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2 U:1
• Conservation: PhyloP100: -1.21

Genes affected

KCNJ11 (HGNC:6257): (potassium inwardly rectifying channel subfamily J member 11) 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. The encoded protein, which has a greater tendency to allow potassium to flow into a cell rather than out of a cell, is controlled by G-proteins and is found associated with the sulfonylurea receptor SUR. Mutations in this gene are a cause of familial persistent hyperinsulinemic hypoglycemia of infancy (PHHI), an autosomal recessive disorder characterized by unregulated insulin secretion. Defects in this gene may also contribute to autosomal dominant non-insulin-dependent diabetes mellitus type II (NIDDM), transient neonatal diabetes mellitus type 3 (TNDM3), and permanent neonatal diabetes mellitus (PNDM). Multiple alternatively spliced transcript variants that encode different protein isoforms have been described for this gene. [provided by RefSeq, Oct 2009]

ACMG classification

Verdict is Pathogenic. Variant got 11 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 40 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-17388056-G-T is Pathogenic according to our data. Variant chr11-17388056-G-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 8673.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNJ11	NM_000525.4	c.36C>A	p.Tyr12*	stop_gained	Exon 1 of 1	ENST00000339994.5	NP_000516.3
KCNJ11	NM_001377296.1	c.-55C>A		5_prime_UTR_variant	Exon 2 of 3		NP_001364225.1
KCNJ11	NM_001166290.2	c.-16-210C>A		intron_variant	Intron 1 of 1		NP_001159762.1
KCNJ11	NM_001377297.1	c.-16-210C>A		intron_variant	Intron 1 of 1		NP_001364226.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNJ11	ENST00000339994.5	c.36C>A	p.Tyr12*	stop_gained	Exon 1 of 1	6	NM_000525.4	ENSP00000345708.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1460054 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 726452

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Pathogenic:1

Mar 23, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

For these reasons, this variant has been classified as Pathogenic. This sequence change creates a premature translational stop signal (p.Tyr12*) in the KCNJ11 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 379 amino acid(s) of the KCNJ11 protein. This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with congenital hyperinsulinism (PMID: 9356020). ClinVar contains an entry for this variant (Variation ID: 8673). Experimental studies have shown that this variant affects KCNJ11 protein function (PMID: 9356020, 20694718). -

Hyperinsulinemic hypoglycemia, familial, 2 Pathogenic:1

Nov 01, 1997

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Maturity onset diabetes mellitus in young Uncertain:1

-

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: research

Mutations in KCNJ11 gene can cause decreased production and secretion of insulin. This can lead to MODY which is responsive to oral sulfonylureas. However, No sufficient evidence is found to ascertain the role of this particular variant (rs104894236) in MODY. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	29
DANN	Uncertain	0.99
Eigen	Benign	-0.13
Eigen_PC	Benign	-0.42
FATHMM_MKL	Benign	0.41	N
Vest4		0.77
ClinPred		0.99	D
GERP RS		-2.2

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: rs104894236; hg19: chr11-17409603;