rs142817246

chr7-44149821-C-T

Variant summary

Our verdict is Benign. Variant got -21 ACMG points: 0P and 21B. BP4_Strong BP6_Very_Strong BP7 BS1 BS2

The NM_000162.5(GCK):c.618G>A(p.Thr206=) 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:10
• Conservation: PhyloP100: -5.58

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]

LOC105375258 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -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 [Likely_benign]. Clinvar id is 36235.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr7-44149821-C-T is described in Lovd as [Likely_benign].
• 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 male gnomad4 subpopulation. This position pass quality control queck.
• BS2: High Homozygotes in GnomAd at 3 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GCK	NM_000162.5	c.618G>A	p.Thr206=	synonymous_variant	6/10	ENST00000403799.8
LOC105375258	XR_927223.3	n.352C>T		non_coding_transcript_exon_variant	3/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GCK	ENST00000403799.8	c.618G>A	p.Thr206=	synonymous_variant	6/10	1	NM_000162.5	P1

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

GnomAD3 exomes AF: 0.000998 AC: 251 AN: 251444 Hom.: 0 AF XY: 0.000751 AC XY: 102 AN XY: 135902

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 SAS exome AF: 0.0000653

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

Gnomad4 AFR exome AF: 0.0105

Gnomad4 AMR exome AF: 0.000961

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000232

Gnomad4 FIN exome AF: 0.0000187

Gnomad4 NFE exome AF: 0.0000306

Gnomad4 OTH exome AF: 0.000811

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

Gnomad4 AFR AF: 0.0123

Gnomad4 AMR AF: 0.00190

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000294

Gnomad4 OTH AF: 0.00425

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:10

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

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

Likely benign, criteria provided, single submitter	clinical testing;curation	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Aug 18, 2011	- -
Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 12, 2018	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 mellitus in young Benign:2

Benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 26, 2020	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. -
Benign, criteria provided, single submitter	research	Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic	-	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

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Feb 21, 2021	- -
Benign, criteria provided, single submitter	clinical testing	Invitae	Dec 25, 2023	- -

not specified Benign:1

Benign, criteria provided, single submitter

clinical testing

Genetic Services Laboratory, University of Chicago

May 12, 2017

- -

Transient Neonatal Diabetes, Recessive Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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

Likely benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 12, 2018

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

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

LitVar

Other links and lift over

dbSNP: rs142817246; hg19: chr7-44189420;