rs193922323

Variant summary

Our verdict is Pathogenic. The variant received 19 ACMG points: 19P and 0B. PM1PM2PM5PP2PP3_StrongPP5_Very_Strong

The NM_000162.5(GCK):​c.704T>C​(p.Met235Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,246 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 Pathogenic (★★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M235V) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 33)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

GCK
NM_000162.5 missense

Scores

13
5
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:1

Conservation

PhyloP100: 9.27

Publications

11 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 19 ACMG points.

PM1
In a hotspot region, there are 16 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000162.5
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr7-44147810-T-C is described in ClinVar as Pathogenic. ClinVar VariationId is 381599.Status of the report is reviewed_by_expert_panel, 3 stars.
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, 0.986
PP5
Variant 7-44147809-A-G is Pathogenic according to our data. Variant chr7-44147809-A-G is described in ClinVar as Pathogenic. ClinVar VariationId is 36248.Status of the report is reviewed_by_expert_panel, 3 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GCKNM_000162.5 linkc.704T>C p.Met235Thr missense_variant Exon 7 of 10 ENST00000403799.8 NP_000153.1 P35557-1Q53Y25

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GCKENST00000403799.8 linkc.704T>C p.Met235Thr missense_variant Exon 7 of 10 1 NM_000162.5 ENSP00000384247.3 P35557-1

Frequencies

GnomAD3 genomes
Cov.:
33
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461246
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
726936
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52794
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1112000
Other (OTH)
AF:
0.00
AC:
0
AN:
60390
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
33
Alfa
AF:
0.00000989
Hom.:
0

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Maturity-onset diabetes of the young type 2 Pathogenic:2
Aug 18, 2011
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing;curation

- -

Apr 04, 2024
Centre for Inherited Metabolic Diseases, Karolinska University Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Jan 11, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 235 of the GCK protein (p.Met235Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with maturity-onset diabetes of the young (PMID: 14517946). ClinVar contains an entry for this variant (Variation ID: 36248). 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 with a negative predictive value of 80%. This variant disrupts the p.Met235 amino acid residue in GCK. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 17186219, 24323243). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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
0.95
BayesDel_addAF
Pathogenic
0.56
D
BayesDel_noAF
Pathogenic
0.56
CADD
Pathogenic
28
DANN
Uncertain
0.99
DEOGEN2
Pathogenic
0.93
.;D;.;.;.
Eigen
Pathogenic
0.76
Eigen_PC
Pathogenic
0.74
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D;D;.;D;D
M_CAP
Pathogenic
0.63
D
MetaRNN
Pathogenic
0.99
D;D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.5
.;M;.;.;.
PhyloP100
9.3
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-5.8
.;D;D;D;D
REVEL
Pathogenic
0.97
Sift
Uncertain
0.0010
.;D;D;D;D
Sift4G
Uncertain
0.0020
D;D;D;D;D
Polyphen
0.71
P;P;P;P;.
Vest4
0.95
MutPred
0.92
.;Loss of helix (P = 0.1299);.;.;.;
MVP
0.99
MPC
2.2
ClinPred
0.99
D
GERP RS
5.3
Varity_R
0.96
gMVP
0.99
Mutation Taster
=0/100
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

Publications

Other links and lift over

dbSNP: rs193922323; hg19: chr7-44187408; API