rs193922329

Variant names:

• chr7-44153433-G-A
• rs193922329
• NM_000162.5:c.76C>T

Your query was ambiguous. Multiple possible variants found:

• chr7-44153433-G-A
• chr7-44153433-G-C

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000162.5(GCK):​c.76C>T​(p.Gln26*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,734 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 Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GCK NM_000162.5 stop_gained
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:9
• Conservation: PhyloP100: 2.25
• Publications: 5 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

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. There are 612 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-44153433-G-A is Pathogenic according to our data. Variant chr7-44153433-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 36256.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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.76C>T	p.Gln26*	stop_gained	Exon 2 of 10	NP_000153.1
	GCK	NM_033507.3		c.79C>T	p.Gln27*	stop_gained	Exon 2 of 10	NP_277042.1
	GCK	NM_033508.3		c.73C>T	p.Gln25*	stop_gained	Exon 3 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.76C>T	p.Gln26*	stop_gained	Exon 2 of 10	ENSP00000384247.3
	GCK	ENST00000395796.8	TSL:1	n.*74C>T		non_coding_transcript_exon	Exon 3 of 11	ENSP00000379142.4
	GCK	ENST00000395796.8	TSL:1	n.*74C>T		3_prime_UTR	Exon 3 of 11	ENSP00000379142.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461734 Hom.: 0 Cov.: 34 AF XY: 0.00 AC XY: 0 AN XY: 727162

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

American (AMR) AF: 0.00 AC: 0 AN: 44724

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: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53280

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1112002

Other (OTH) AF: 0.00 AC: 0 AN: 60388

GnomAD4 genome Cov.: 32

Alfa AF: 0.00000497 Hom.: 0

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:9

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:4

Jun 14, 2016

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Apr 21, 2020

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Apr 23, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant is not present in population databases (ExAC no frequency). This variant has been observed in individual(s) with maturity-onset diabetes of the young (PMID: 24735133, 11508276, 24804978, 28726111). ClinVar contains an entry for this variant (Variation ID: 36256). For these reasons, this variant has been classified as Pathogenic. This sequence change creates a premature translational stop signal (p.Gln26*) in the GCK gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in GCK are known to be pathogenic (PMID: 24323243).

Feb 20, 2025

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Nonsense variant predicted to result in protein truncation or nonsense mediated decay in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 14981344, 25525159, 35472491, 36257325, 36504295, 36208030, 35177841, 11508276, 24735133)

Maturity-onset diabetes of the young type 2 Pathogenic:3

Aug 02, 2022

Geisinger Clinic, Geisinger Health System

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

PVS1, PM2, PP1, PS4

National Newborn Screening Laboratory, Hospital Nacional de Niños

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This is a nonsense variant in the GCK gene, where loss of function is a known mechanism of disease (PVS1). This variant results in a truncated protein by creating a premature stop codon. It is not present in population databases (GnomAD exomes, GnomAD genomes) (PM2).

Jul 15, 2025

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GCK c.76C>T (p.Gln26X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant was absent in 251428 control chromosomes. c.76C>T has been observed in individuals affected with Maturity-Onset Diabetes Of The Young Type 2 (e.g., Massa_2001, Mirshahi_2022). These data indicate that the variant is likely to be associated with disease. The following publications have been ascertained in the context of this evaluation (PMID: 11508276, 36257325). ClinVar contains an entry for this variant (Variation ID: 36256). Based on the evidence outlined above, the variant was classified as pathogenic.

GCK-related disorder Pathogenic:1

Sep 29, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The GCK c.76C>T variant is predicted to result in premature protein termination (p.Gln26*). This variant has been reported in several individuals with maturity-onset diabetes of the young (MODY) (Massa et al. 2001. PubMed ID: 11508276; Costantini et al. 2014. PubMed ID: 24735133; Table S1, Mirshahi et al. 2022. PubMed ID: 36257325; Yorifuji et al. 2022. PubMed ID: 36504295), in an individual with type 2 diabetes (Table S6, Jurgens et al. 2022. PubMed ID: 35177841), and in three individuals with monogenic diabetes (Vaxillaire et al. 2020. PubMed ID: 33242514). This variant has not been reported in a large population database, indicating this variant is rare. Nonsense variants in GCK are expected to be pathogenic. This variant is interpreted as pathogenic.

Maturity onset diabetes mellitus in young Pathogenic:1

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

Potent mutations in GCK gene is associated with poor secretion of insulin. Its associated with milder forms of diabetes, which can be controlled by diet . However, there is no sufficient evidence to ascertain the significance of rs193922329 in MODY, yet.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	42
DANN	Uncertain	1.0
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.86
FATHMM_MKL	Uncertain	0.85	D
PhyloP100		2.3
Vest4		0.95
GERP RS		5.3
Mutation Taster		=0/200	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: rs193922329; hg19: chr7-44193032;