NM_000162.5:c.618G>A

Variant names:

• chr7-44149821-C-T
• rs142817246
• NM_000162.5:c.618G>A

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_Strong BP6_Very_Strong BP7 BS1 BS2

The NM_000162.5(GCK):​c.618G>A​(p.Thr206Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000639 in 1,614,130 control chromosomes in the GnomAD database, including 6 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.0036 (3 hom., cov: 32)
  • Exomes 𝑓: 0.00033 (3 hom.)
• Consequence: GCK NM_000162.5 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:11
• Conservation: PhyloP100: -5.58
• 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

LOC105375258 (HGNC:):

ACMG classification

Our verdict: Benign. The variant received -21 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.67).
• BP6: Variant 7-44149821-C-T is Benign according to our data. Variant chr7-44149821-C-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 36235.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=-5.58 with no splicing effect.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.00361 (550/152286) while in subpopulation AFR AF = 0.0123 (510/41550). AF 95% confidence interval is 0.0114. There are 3 homozygotes in GnomAd4. There are 249 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
• BS2: High Homozygotes in GnomAd4 at 3 AR,AD gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GCK	NM_000162.5	c.618G>A	p.Thr206Thr	synonymous_variant	Exon 6 of 10	ENST00000403799.8	NP_000153.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GCK	ENST00000403799.8	c.618G>A	p.Thr206Thr	synonymous_variant	Exon 6 of 10	1	NM_000162.5	ENSP00000384247.3

Frequencies

GnomAD3 genomes AF: 0.00361 AC: 550 AN: 152168 Hom.: 3 Cov.: 32

Gnomad AFR AF: 0.0123

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00190

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: 0.00430

GnomAD2 exomes AF: 0.000998 AC: 251 AN: 251444 AF XY: 0.000751

Gnomad AFR exome AF: 0.0130

Gnomad AMR exome AF: 0.000954

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.000326

GnomAD4 exome AF: 0.000329 AC: 481 AN: 1461844 Hom.: 3 Cov.: 33 AF XY: 0.000308 AC XY: 224 AN XY: 727224

African (AFR) AF: 0.0105 AC: 351 AN: 33480

American (AMR) AF: 0.000961 AC: 43 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.0000383 AC: 1 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000232 AC: 2 AN: 86254

European-Finnish (FIN) AF: 0.0000187 AC: 1 AN: 53392

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

European-Non Finnish (NFE) AF: 0.0000306 AC: 34 AN: 1111996

Other (OTH) AF: 0.000811 AC: 49 AN: 60394

GnomAD4 genome AF: 0.00361 AC: 550 AN: 152286 Hom.: 3 Cov.: 32 AF XY: 0.00334 AC XY: 249 AN XY: 74454

African (AFR) AF: 0.0123 AC: 510 AN: 41550

American (AMR) AF: 0.00190 AC: 29 AN: 15302

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3468

East Asian (EAS) AF: 0.00 AC: 0 AN: 5170

South Asian (SAS) AF: 0.00 AC: 0 AN: 4824

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10616

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000294 AC: 2 AN: 68034

Other (OTH) AF: 0.00425 AC: 9 AN: 2116

Alfa AF: 0.00183 Hom.: 0

Bravo AF: 0.00414

Asia WGS AF: 0.000289 AC: 1 AN: 3478

EpiCase AF: 0.0000545

EpiControl AF: 0.0000593

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:11

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:3

May 12, 2017

Genetic Services Laboratory, University of Chicago

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 06, 2024

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

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Feb 29, 2024

Athena Diagnostics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Maturity onset diabetes mellitus in young Benign:2

Mar 26, 2020

Ambry Genetics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

-

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

Significance: Benign

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 rs142817246 in MODY, yet. -

not provided Benign:2

Feb 21, 2021

GeneDx

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dec 31, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Transient Neonatal Diabetes, Recessive Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

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

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Permanent neonatal diabetes mellitus Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

Hyperinsulinism due to glucokinase deficiency Benign:1

Jan 12, 2018

Illumina Laboratory Services, Illumina

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as likely benign is not then subjected to further curation. The score for this variant resulted in a classification of likely benign for this disease. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.67
CADD	Benign	0.041
DANN	Benign	0.82
PhyloP100		-5.6
Mutation Taster		=99/1	polymorphism

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: rs142817246; hg19: chr7-44189420;