Genetic Variant GCK:p.Glu442Lys (chr7-44145210-C-T) – ACMG Classification: Likely_pathogenic (6 pts)

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PP2PP3_ModeratePP5

The NM_000162.5(GCK):c.1324G>A(p.Glu442Lys) variant causes a missense change. The variant allele was found at a frequency of 0.000013 in 1,611,938 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 Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000013 ( 0 hom. )

Consequence

GCK
NM_000162.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:1

Conservation

PhyloP100: 4.63

Publications

16 publications found

Variant links:

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]

GCK Gene-Disease associations (from GenCC):

hyperinsulinism due to glucokinase deficiency
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics, Orphanet
maturity-onset diabetes of the young type 2
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
monogenic diabetes
Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
diabetes mellitus, noninsulin-dependent
Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
permanent neonatal diabetes mellitus 1
Inheritance: AR Classification: STRONG, MODERATE Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae), Ambry Genetics
transient neonatal diabetes mellitus
Inheritance: AR Classification: STRONG Submitted by: Genomics England PanelApp
maturity-onset diabetes of the young
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
permanent neonatal diabetes mellitus
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

GCK links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1

In a hotspot region, there are 11 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_000162.5

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 274 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 3.069 (below the threshold of 3.09). Trascript score misZ: 2.7821 (below the threshold of 3.09). GenCC associations: The gene is linked to transient neonatal diabetes mellitus, monogenic diabetes, permanent neonatal diabetes mellitus 1, diabetes mellitus, noninsulin-dependent, maturity-onset diabetes of the young type 2, hyperinsulinism due to glucokinase deficiency, permanent neonatal diabetes mellitus, maturity-onset diabetes of the young.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.896

PP5

Variant 7-44145210-C-T is Pathogenic according to our data. Variant chr7-44145210-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 521398.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000162.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
GCK	NM_000162.5	MANE Select	c.1324G>A	p.Glu442Lys	missense	Exon 10 of 10	NP_000153.1
GCK	NM_033507.3		c.1327G>A	p.Glu443Lys	missense	Exon 10 of 10	NP_277042.1
GCK	NM_033508.3		c.1321G>A	p.Glu441Lys	missense	Exon 11 of 11	NP_277043.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
GCK	ENST00000403799.8	TSL:1 MANE Select	c.1324G>A	p.Glu442Lys	missense	Exon 10 of 10	ENSP00000384247.3
GCK	ENST00000395796.8	TSL:1	n.*1322G>A		non_coding_transcript_exon	Exon 11 of 11	ENSP00000379142.4
GCK	ENST00000459642.1	TSL:1	n.704G>A		non_coding_transcript_exon	Exon 2 of 2

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152238

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000287

AC:

AN:

243582

AF XY:

0.0000151

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.000149

Gnomad NFE exome

AF:

0.0000183

Gnomad OTH exome

AF:

0.000335

GnomAD4 exome

AF:

0.0000130

AC:

AN:

1459700

Hom.:

Cov.:

AF XY:

0.00000826

AC XY:

AN XY:

726160

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33462

American (AMR)

AF:

0.00

AC:

AN:

44670

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26100

East Asian (EAS)

AF:

0.00

AC:

AN:

39674

South Asian (SAS)

AF:

0.00

AC:

AN:

86086

European-Finnish (FIN)

AF:

0.000154

AC:

AN:

51896

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000810

AC:

AN:

1111716

Other (OTH)

AF:

0.0000332

AC:

AN:

60328

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.472

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152238

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74382

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41478

American (AMR)

AF:

0.00

AC:

AN:

15292

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4832

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10628

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68030

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.0000227

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.0000594

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Pathogenic:1Uncertain:1

Feb 08, 2019

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. Experimental studies have shown that this missense change alters GCK activity in vitro (PMID: 19884385, 21831042). This variant has been reported in individuals affected with hypoglycemia (PMID: 19884385, 27188453). This variant is present in population databases (rs758737171, ExAC 0.003%). This sequence change replaces glutamic acid with lysine at codon 442 of the GCK protein (p.Glu442Lys). The glutamic acid residue is highly conserved and there is a small physicochemical difference between glutamic acid and lysine.

Mar 03, 2025

GeneDx

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Reported in a patient with neonatal hypoglycemia and also present in two affected relatives (PMID: 19884385); Published functional studies demonstrate that the variant p.(E442K) protein results in a higher affinity for glucose (PMID: 21831042, 19884385); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Missense variants in this gene are a common cause of disease and they are underrepresented in the general population; This variant is associated with the following publications: (PMID: 31589614, 27188453, 21831042, 19884385, 32041611, 34680961, 36257325, 28247534)

Inborn genetic diseases

Pathogenic:1

Nov 29, 2016

Ambry Genetics

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Permanent neonatal diabetes mellitus

Pathogenic:1

Feb 05, 2022

DASA

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.1324G>A;p.(Glu442Lys) missense variant has been observed in affected individual(s) and ClinVar contains an entry for this variant (PMID: 28247534; 27188453; 19884385) - PS4. The variant is present at low allele frequencies population databases (rs758737171 – gnomAD 0.0001314%; ABraOM no frequency - http://abraom.ib.usp.br/) - PM2_supporting. The variant co-segregated with disease in multiple affected family members (PP1: 19884385) - PP1. Multiple lines of computational evidence support a deleterious effect on the gene or gene product - PP3. In summary, the currently available evidence indicates that the variant is likely pathogenic.

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Pathogenic

0.44

BayesDel_noAF

Pathogenic

0.42

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.51

Eigen

Uncertain

0.22

Eigen_PC

Uncertain

0.33

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.95

M_CAP

Pathogenic

0.59

MetaRNN

Pathogenic

0.90

MetaSVM

Pathogenic

1.0

MutationAssessor

Benign

1.4

PhyloP100

4.6

PrimateAI

Uncertain

0.74

PROVEAN

Uncertain

-3.8

REVEL

Pathogenic

0.83

Sift

Uncertain

0.020

Sift4G

Uncertain

0.012

Polyphen

0.49

Vest4

0.83

MVP

0.89

MPC

1.5

ClinPred

0.91

GERP RS

5.0

Varity_R

0.77

gMVP

0.94

Mutation Taster

=2/98

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over