rs193922340

Variant names:

• chr7-44146530-C-A
• rs193922340
• NM_000162.5:c.952G>T

Your query was ambiguous. Multiple possible variants found:

• chr7-44146530-C-A
• chr7-44146530-C-G
• chr7-44146530-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PM5 PP2 PP3 PM2_Supporting

This summary comes from the ClinGen Evidence Repository: The c.952G>T variant in the glucokinase gene, GCK, causes an amino acid change of glycine to tryptophan at codon 318 (p.(Gly318Trp)) of NM_000162.5. GCK is defined by the ClinGen MDEP as a gene that has a low rate of benign missense variation and has pathogenic missense variants as a common mechanism of disease (PP2). This variant has an incomputable gnomAD v4.1.0 Grpmax filtering allele frequency due to zero copies in the European non-Finnish subpopulation and 1 copy in any other subpopulation, thereby meeting the ClinGen MDEP threshold criteria for PM2_Supporting (ENF Grpmax FAF <= 0.000003) (PM2_Supporting). This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.9, which is greater than the MDEP VCEP threshold of 0.70 (PP3). This variant was identified in a single individual with hyperglycemia; however, PS4_Moderate cannot be applied because this number is below the ClinGen MDEP threshold and PP4 cannot be evaluated due to insufficient clinical data (internal lab contributors). Another missense variant, c.952G>A, p.(Gly318Arg) has been interpreted as pathogenic by the ClinGen MDEP, and p.(Gly318Trp) has a greater Grantham distance (PM5). In summary, c.952G>T meets the criteria to be classified as a variant of uncertain significance for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 1.3.0, approved 8/11/23): PM5, PM2_Supporting, PP2, PP3. LINK:https://erepo.genome.network/evrepo/ui/classification/CA213870/MONDO:0015967/086

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GCK NM_000162.5 missense
• Clinical Significance: Uncertain significance reviewed by expert panel P:3 U:1
• Conservation: PhyloP100: 7.76
• Publications: 18 publications found

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

ENSG00000300758 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM5: For more information check the summary or visit ClinGen Evidence Repository.
• PP2: For more information check the summary or visit ClinGen Evidence Repository.
• PP3: For more information check the summary or visit ClinGen Evidence Repository.

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GCK	NM_000162.5	MANE Select	c.952G>T	p.Gly318Trp	missense	Exon 8 of 10	NP_000153.1
	GCK	NM_033507.3		c.955G>T	p.Gly319Trp	missense	Exon 8 of 10	NP_277042.1
	GCK	NM_033508.3		c.949G>T	p.Gly317Trp	missense	Exon 9 of 11	NP_277043.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GCK	ENST00000403799.8	TSL:1 MANE Select	c.952G>T	p.Gly318Trp	missense	Exon 8 of 10	ENSP00000384247.3
	GCK	ENST00000395796.8	TSL:1	n.*950G>T		non_coding_transcript_exon	Exon 9 of 11	ENSP00000379142.4
	GCK	ENST00000395796.8	TSL:1	n.*950G>T		3_prime_UTR	Exon 9 of 11	ENSP00000379142.4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000807 AC: 2 AN: 247698 AF XY: 0.00000743

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: 0.0000529

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1458150 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 725650

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26132

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86258

European-Finnish (FIN) AF: 0.0000201 AC: 1 AN: 49774

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5764

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1111972

Other (OTH) AF: 0.00 AC: 0 AN: 60352

GnomAD4 genome Cov.: 33

Alfa AF: 0.00000497 Hom.: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:3 Uncertain:1

Revision: reviewed by expert panel

Submissions by phenotype

Maturity-onset diabetes of the young type 2 Pathogenic:1

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

Maturity onset diabetes mellitus in young Pathogenic:1

Feb 06, 2016

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.G318W variant (also known as c.952G>T), located in coding exon 8 of the GCK gene, results from a G to T substitution at nucleotide position 952. The glycine at codon 318 is replaced by tryptophan, an amino acid with highly dissimilar properties. This variant results in perturbation of the structure as much as known pathogenic variants (Zhang, R., Zhou, M., Peterson, S., Anderson, W., Joachimiak, A. The crystal structure of the adenylosuccinate synthetase from Yersinia pestis CO92. PDB ID: 3HID. http://www.rcsb.org/pdb/explore/explore.do?structureId=3HID). This variant was previously reported in the SNPDatabase as rs193922340. Based on data from the NHLBI Exome Sequencing Project (ESP), no alterations were observed among 13006 alleles tested (0.0%). Allele frequency data for this nucleotide position is not currently available from the 1000 Genomes Project. This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic.

not provided Pathogenic:1

Dec 02, 2024

Athena Diagnostics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The frequency of this variant in the general population is consistent with pathogenicity. (http://gnomad.broadinstitute.org) This variant has been identified in at least one individual with clinical features of MODY. Assessment of experimental evidence suggests this variant results in abnormal protein function. (PMID: 37101203) At least one other missense variant at this codon is considered to be pathogenic or likely pathogenic, suggesting this variant may also cause disease.

Monogenic diabetes Uncertain:1

Jun 02, 2025

ClinGen Monogenic Diabetes Variant Curation Expert Panel

Significance: Uncertain significance

Review Status: reviewed by expert panel

Collection Method: curation

The c.952G>T variant in the glucokinase gene, GCK, causes an amino acid change of glycine to tryptophan at codon 318 (p.(Gly318Trp)) of NM_000162.5. GCK is defined by the ClinGen MDEP as a gene that has a low rate of benign missense variation and has pathogenic missense variants as a common mechanism of disease (PP2). This variant has an incomputable gnomAD v4.1.0 Grpmax filtering allele frequency due to zero copies in the European non-Finnish subpopulation and 1 copy in any other subpopulation, thereby meeting the ClinGen MDEP threshold criteria for PM2_Supporting (ENF Grpmax FAF <= 0.000003) (PM2_Supporting). This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.9, which is greater than the MDEP VCEP threshold of 0.70 (PP3). This variant was identified in a single individual with hyperglycemia; however, PS4_Moderate cannot be applied because this number is below the ClinGen MDEP threshold and PP4 cannot be evaluated due to insufficient clinical data (internal lab contributors). Another missense variant, c.952G>A, p.(Gly318Arg) has been interpreted as pathogenic by the ClinGen MDEP, and p.(Gly318Trp) has a greater Grantham distance (PM5). In summary, c.952G>T meets the criteria to be classified as a variant of uncertain significance for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP (specification version 2.0.0, approved 2/17/2025): PM5, PM2_Supporting, PP2, PP3.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.93
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
CADD	Pathogenic	33
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.95	D
Eigen	Uncertain	0.49
Eigen_PC	Uncertain	0.33
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.6	H
PhyloP100		7.8
PrimateAI	Uncertain	0.71	T
PROVEAN	Pathogenic	-7.3	D
REVEL	Pathogenic	0.90
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.84
MutPred		0.88		Loss of disorder (P = 0.0132)
MVP		0.94
MPC		2.3
ClinPred		1.0	D
GERP RS		3.9
PromoterAI		0.0094	Neutral
Varity_R		0.98
gMVP		0.98
Mutation Taster		=3/97	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

Other links and lift over

dbSNP: rs193922340; hg19: chr7-44186129;