chr11-17387124-T-TC

Variant names:

• chr11-17387124-T-TC
• rs1554901596
• NM_000525.4:c.967dupG

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PVS1_Strong PM2 PP5

The NM_000525.4(KCNJ11):​c.967dupG​(p.Asp323GlyfsTer28) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. D323D) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNJ11 NM_000525.4 frameshift
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 7.91
• Publications: 0 publications found

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]

KCNJ11 Gene-Disease associations (from GenCC):

• diabetes mellitus, transient neonatal, 3

  Inheritance: AD Classification: DEFINITIVE, STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P
• monogenic diabetes

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• hyperinsulinemic hypoglycemia, familial, 2

  Inheritance: AR, AD Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), G2P, Ambry Genetics
• diabetes mellitus, noninsulin-dependent

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• diabetes mellitus, permanent neonatal 2

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• maturity-onset diabetes of the young type 13

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• autosomal dominant hyperinsulinism due to Kir6.2 deficiency

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• DEND syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• intermediate DEND syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• maturity-onset diabetes of the young

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• permanent neonatal diabetes mellitus

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• transient neonatal diabetes mellitus

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive hyperinsulinism due to Kir6.2 deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• diazoxide-resistant focal hyperinsulinism due to Kir6.2 deficiency

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 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 8 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 11-17387124-T-TC is Pathogenic according to our data. Variant chr11-17387124-T-TC is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 478917.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
KCNJ11	NM_000525.4	c.967dupG	p.Asp323GlyfsTer28	frameshift_variant	Exon 1 of 1	ENST00000339994.5	NP_000516.3
KCNJ11	NM_001166290.2	c.706dupG	p.Asp236GlyfsTer28	frameshift_variant	Exon 2 of 2		NP_001159762.1
KCNJ11	NM_001377296.1	c.706dupG	p.Asp236GlyfsTer28	frameshift_variant	Exon 3 of 3		NP_001364225.1
KCNJ11	NM_001377297.1	c.706dupG	p.Asp236GlyfsTer28	frameshift_variant	Exon 2 of 2		NP_001364226.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
KCNJ11	ENST00000339994.5	c.967dupG	p.Asp323GlyfsTer28	frameshift_variant	Exon 1 of 1	6	NM_000525.4	ENSP00000345708.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 67

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Type 2 diabetes mellitus;C4225365:Maturity-onset diabetes of the young type 13 Pathogenic:1

Aug 31, 2017

Shenzhen Institute of Pediatrics, Shenzhen Children's Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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 may be responsive to oral sulfonylureas. It is also associated with with Neonatal Diabetes. However, no sufficient evidence is found to ascertain the role of rs1554901596 variant in MODY yet. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		7.9
Mutation Taster		=3/197	disease causing (ClinVar)

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: rs1554901596; hg19: chr11-17408671;