rs200698755

Variant names:

• chr7-44145125-G-A
• rs200698755
• ENST00000395796.8:n.*1407C>T

Variant summary

Our verdict is Benign. The variant received -9 ACMG points: 0P and 9B. BP4_Strong BP6 BS1

The ENST00000395796.8(GCK):​n.*1407C>T variant causes a non coding transcript exon change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00013 in 1,609,784 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.00045 (0 hom., cov: 33)
  • Exomes 𝑓: 0.000097 (1 hom.)
• Consequence: GCK ENST00000395796.8 non_coding_transcript_exon
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:5
• Conservation: PhyloP100: -0.236
• Publications: 1 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: Benign. The variant received -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.78).
• BP6: Variant 7-44145125-G-A is Benign according to our data. Variant chr7-44145125-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 255399.
• BS1: Variant frequency is greater than expected in population afr. GnomAd4 allele frequency = 0.000453 (69/152342) while in subpopulation AFR AF = 0.00147 (61/41592). AF 95% confidence interval is 0.00117. There are 0 homozygotes in GnomAd4. There are 27 alleles in the male GnomAd4 subpopulation. Median coverage is 33. This position passed quality control check.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GCK	NM_000162.5	c.*11C>T		3_prime_UTR_variant	Exon 10 of 10	ENST00000403799.8	NP_000153.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GCK	ENST00000403799.8	c.*11C>T		3_prime_UTR_variant	Exon 10 of 10	1	NM_000162.5	ENSP00000384247.3

Frequencies

GnomAD3 genomes AF: 0.000440 AC: 67 AN: 152224 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00142

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000327

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: 0.0000147

Gnomad OTH AF: 0.000955

GnomAD2 exomes AF: 0.000174 AC: 42 AN: 241972 AF XY: 0.000144

Gnomad AFR exome AF: 0.00218

Gnomad AMR exome AF: 0.000146

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000183

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000967 AC: 141 AN: 1457442 Hom.: 1 Cov.: 31 AF XY: 0.0000979 AC XY: 71 AN XY: 724998

African (AFR) AF: 0.00224 AC: 75 AN: 33454

American (AMR) AF: 0.000202 AC: 9 AN: 44614

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26092

East Asian (EAS) AF: 0.00 AC: 0 AN: 39642

South Asian (SAS) AF: 0.0000233 AC: 2 AN: 85912

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 50596

Middle Eastern (MID) AF: 0.000361 AC: 2 AN: 5536

European-Non Finnish (NFE) AF: 0.0000279 AC: 31 AN: 1111348

Other (OTH) AF: 0.000365 AC: 22 AN: 60248

GnomAD4 genome AF: 0.000453 AC: 69 AN: 152342 Hom.: 0 Cov.: 33 AF XY: 0.000362 AC XY: 27 AN XY: 74494

African (AFR) AF: 0.00147 AC: 61 AN: 41592

American (AMR) AF: 0.000327 AC: 5 AN: 15302

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5176

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

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

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68030

Other (OTH) AF: 0.000945 AC: 2 AN: 2116

Alfa AF: 0.000427 Hom.: 0

Bravo AF: 0.000582

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:5

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not specified Benign:3

Sep 01, 2022

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

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: GCK c.*11C>T is located in the untranslated mRNA region downstream of the termination codon. The variant allele was found at a frequency of 0.00018 in 273340 control chromosomes (gnomAD), predominantly at a frequency of 0.0016 within the African or African-American subpopulation in the gnomAD database. The observed variant frequency within African or African-American control individuals in the gnomAD database is approximately 64 fold of the estimated maximal expected allele frequency for a pathogenic variant in GCK causing Monogenic Diabetes (2.5e-05), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African or African-American origin. c.*11C>T has been reported in the literature as a polymorphism routinely seen during sequencing of the GCK gene (Osbak_2009). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Two ClinVar submitters have assessed the variant since 2014: one submitter classified the variant as VUS for Hyperinsulinism and likely benign for Maturity Onset Diabetes of the Young, and one submitter classified the variant as benign. Based on the evidence outlined above, the variant was classified as benign. -

-

PreventionGenetics, part of Exact Sciences

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Sep 30, 2019

Athena Diagnostics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Transient Neonatal Diabetes, Recessive Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Permanent neonatal diabetes mellitus Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

Hyperinsulinism due to glucokinase deficiency Uncertain:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Uncertain significance

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, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

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

Jan 13, 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. -

Maturity onset diabetes mellitus in young Benign:1

-

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 rs200698755 in MODY, yet. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.78
CADD	Benign	3.2
DANN	Benign	0.80
PhyloP100		-0.24

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: rs200698755; hg19: chr7-44184724;