11-17387571-G-T

Position:

• chr11-17387571-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_000525.4(KCNJ11):​c.521C>A​(p.Ala174Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,460,936 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 Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: KCNJ11 NM_000525.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 10.0

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 Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.927

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
KCNJ11	NM_000525.4	c.521C>A	p.Ala174Asp	missense_variant	1/1	ENST00000339994.5	NP_000516.3
KCNJ11	NM_001166290.2	c.260C>A	p.Ala87Asp	missense_variant	2/2		NP_001159762.1
KCNJ11	NM_001377296.1	c.260C>A	p.Ala87Asp	missense_variant	3/3		NP_001364225.1
KCNJ11	NM_001377297.1	c.260C>A	p.Ala87Asp	missense_variant	2/2		NP_001364226.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
KCNJ11	ENST00000339994.5	c.521C>A	p.Ala174Asp	missense_variant	1/1	6	NM_000525.4	ENSP00000345708.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1460936 Hom.: 0 Cov.: 64 AF XY: 0.00 AC XY: 0 AN XY: 726788

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neonatal hypoglycemia Uncertain:1

Uncertain significance, criteria provided, single submitter

research

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

-

Mutations in KCNJ11 gene can cause decreased production and secretion of insulin. This can lead to MODY which may be responsive to oral sulfonylureas. Though rs587783670 (p.A174G) was prevalent in neonatal diabetes, its significance remains inconclusive. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Nov 06, 2023

This sequence change replaces alanine, which is neutral and non-polar, with aspartic acid, which is acidic and polar, at codon 174 of the KCNJ11 protein (p.Ala174Asp). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with KCNJ11-related conditions. ClinVar contains an entry for this variant (Variation ID: 1679207). 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 with a positive predictive value of 95%. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	28
DANN	Uncertain	1.0
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.95	D;.;D
M_CAP	Pathogenic	0.57	D
MetaRNN	Pathogenic	0.93	D;D;D
MetaSVM	Pathogenic	1.0	D
PrimateAI	Pathogenic	0.86	D
PROVEAN	Benign	-2.0	N;N;N
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;.
Vest4		0.90
MutPred		0.76		Gain of ubiquitination at K170 (P = 0.0601);.;.;
MVP		1.0
MPC		2.0
ClinPred		0.99	D
GERP RS		5.2
gMVP		1.0

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: rs587783670; hg19: chr11-17409118;