chr11-17387430-C-G

Variant names:

• chr11-17387430-C-G
• rs768909861
• NM_000525.4:c.662G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_000525.4(KCNJ11):​c.662G>C​(p.Arg221Pro) variant causes a missense 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R221H) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 33)
• Consequence: KCNJ11 NM_000525.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.70
• 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 6 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000525.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.876

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000525.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNJ11	NM_000525.4	MANE Select	c.662G>C	p.Arg221Pro	missense	Exon 1 of 1	NP_000516.3
	KCNJ11	NM_001166290.2		c.401G>C	p.Arg134Pro	missense	Exon 2 of 2	NP_001159762.1
	KCNJ11	NM_001377296.1		c.401G>C	p.Arg134Pro	missense	Exon 3 of 3	NP_001364225.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	KCNJ11	ENST00000339994.5	TSL:6 MANE Select	c.662G>C	p.Arg221Pro	missense	Exon 1 of 1	ENSP00000345708.4
	KCNJ11	ENST00000528731.1	TSL:1	c.401G>C	p.Arg134Pro	missense	Exon 2 of 2	ENSP00000434755.1
	KCNJ11	ENST00000682350.1		c.401G>C	p.Arg134Pro	missense	Exon 2 of 2	ENSP00000508090.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 68

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Feb 06, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt KCNJ11 protein function. This variant has not been reported in the literature in individuals affected with KCNJ11-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 221 of the KCNJ11 protein (p.Arg221Pro).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.48	D
BayesDel_noAF	Pathogenic	0.46
CADD	Pathogenic	27
DANN	Uncertain	1.0
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Uncertain	0.95	D
M_CAP	Uncertain	0.23	D
MetaRNN	Pathogenic	0.88	D
MetaSVM	Pathogenic	0.99	D
PhyloP100		2.7
PrimateAI	Uncertain	0.57	T
PROVEAN	Uncertain	-4.2	D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.0020	D
Vest4		0.58
MutPred		0.66		Loss of MoRF binding (P = 0.019)
MVP		0.99
MPC		1.8
ClinPred		1.0	D
GERP RS		5.3
gMVP		0.99
Mutation Taster		=44/56	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: rs768909861; hg19: chr11-17408977;