chr7-44145167-G-A

Variant names:

• chr7-44145167-G-A
• rs104894014
• NM_000162.5:c.1367C>T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1 PM2 PP3_Strong PP5_Very_Strong

The NM_000162.5(GCK):​c.1367C>T​(p.Ala456Val) variant causes a missense change involving the alteration of a 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 Pathogenic (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: GCK NM_000162.5 missense
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.38

Genes affected

GCK (HGNC:4195): (glucokinase) This gene encodes a member of the hexokinase family of proteins. Hexokinases phosphorylate glucose to produce glucose-6-phosphate, the first step in most glucose metabolism pathways. In contrast to other forms of hexokinase, this enzyme is not inhibited by its product glucose-6-phosphate but remains active while glucose is abundant. The use of multiple promoters and alternative splicing of this gene result in distinct protein isoforms that exhibit tissue-specific expression in the pancreas and liver. In the pancreas, this enzyme plays a role in glucose-stimulated insulin secretion, while in the liver, this enzyme is important in glucose uptake and conversion to glycogen. Mutations in this gene that alter enzyme activity have been associated with multiple types of diabetes and hyperinsulinemic hypoglycemia. [provided by RefSeq, Aug 2017]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM1: In a helix (size 12) in uniprot entity HXK4_HUMAN there are 4 pathogenic changes around while only 0 benign (100%) in NM_000162.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.982
• PP5: Variant 7-44145167-G-A is Pathogenic according to our data. Variant chr7-44145167-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 16143.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GCK	NM_000162.5	c.1367C>T	p.Ala456Val	missense_variant	Exon 10 of 10	ENST00000403799.8	NP_000153.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GCK	ENST00000403799.8	c.1367C>T	p.Ala456Val	missense_variant	Exon 10 of 10	1	NM_000162.5	ENSP00000384247.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Dec 12, 2017

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 28, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 456 of the GCK protein (p.Ala456Val). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with hyperinsulinemic hypoglycemia (PMID: 11916951, 14687251). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 16143). 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 not expected to disrupt GCK protein function. Experimental studies have shown that this missense change affects GCK function (PMID: 11916951, 15987895, 17082186, 17353190, 19146401, 21831042, 22194744). For these reasons, this variant has been classified as Pathogenic. -

Hyperinsulinism due to glucokinase deficiency Pathogenic:1

Apr 01, 2002

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
BayesDel_addAF	Pathogenic	0.54	D
BayesDel_noAF	Pathogenic	0.54
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.56	.;D;D;.;.;.
Eigen	Pathogenic	0.74
Eigen_PC	Pathogenic	0.78
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D;D;D;.;D;D
M_CAP	Pathogenic	0.67	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Uncertain	2.6	.;.;M;.;.;.
PrimateAI	Uncertain	0.66	T
PROVEAN	Uncertain	-3.4	.;D;D;D;D;D
REVEL	Pathogenic	0.88
Sift	Uncertain	0.0010	.;D;D;D;D;D
Sift4G	Uncertain	0.0020	D;T;D;D;D;D
Polyphen		1.0	D;.;P;D;P;P
Vest4		0.85
MutPred		0.92		.;.;Loss of ubiquitination at K459 (P = 0.0573);.;.;.;
MVP		0.98
MPC		1.4
ClinPred		0.99	D
GERP RS		5.8
Varity_R		0.93
gMVP		0.98

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: rs104894014; hg19: chr7-44184766;