rs1554335752

Variant names:

• chr7-44152338-CA-C
• rs1554335752
• NM_000162.5:c.295delT

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000162.5(GCK):​c.295delT​(p.Trp99GlyfsTer3) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 33)
• Consequence: GCK NM_000162.5 frameshift
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 5.27

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]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 7-44152338-CA-C is Pathogenic according to our data. Variant chr7-44152338-CA-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 435304.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GCK	NM_000162.5	c.295delT	p.Trp99GlyfsTer3	frameshift_variant	Exon 3 of 10	ENST00000403799.8	NP_000153.1
GCK	NM_033507.3	c.298delT	p.Trp100GlyfsTer3	frameshift_variant	Exon 3 of 10		NP_277042.1
GCK	NM_033508.3	c.292delT	p.Trp98GlyfsTer3	frameshift_variant	Exon 4 of 11		NP_277043.1
GCK	NM_001354800.1	c.295delT	p.Trp99GlyfsTer3	frameshift_variant	Exon 3 of 11		NP_001341729.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GCK	ENST00000403799.8	c.295delT	p.Trp99GlyfsTer3	frameshift_variant	Exon 3 of 10	1	NM_000162.5	ENSP00000384247.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Maturity onset diabetes mellitus in young Pathogenic:2

Aug 07, 2018

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.295delT pathogenic mutation, located in coding exon 3 of the GCK gene, results from a deletion of one nucleotide at nucleotide position 295, causing a translational frameshift with a predicted alternate stop codon (p.W99Gfs*3). This alteration is expected to result in loss of function by premature protein truncation or nonsense-mediated mRNA decay. As such, this alteration is interpreted as a disease-causing mutation. -

-

Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

Significance: Likely 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 rs1554335752 in MODY, yet. -

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

Aug 20, 2015

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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Computational scores

Source: dbNSFP v4.3

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs1554335752; hg19: chr7-44191937;