7-44150062-GC-G

Position:

• chr7-44150062-GC-G

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.485del​(p.Gly162AlafsTer42) variant causes a frameshift, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,194 control chromosomes in the GnomAD database, with no homozygous occurrence. 1/1 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: GCK NM_000162.5 frameshift, splice_region
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 7.91

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 7-44150062-GC-G is Pathogenic according to our data. Variant chr7-44150062-GC-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 447407.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GCK	NM_000162.5	c.485del	p.Gly162AlafsTer42	frameshift_variant, splice_region_variant	5/10	ENST00000403799.8	NP_000153.1
GCK	NM_033507.3	c.488del	p.Gly163AlafsTer42	frameshift_variant, splice_region_variant	5/10		NP_277042.1
GCK	NM_033508.3	c.482del	p.Gly161AlafsTer42	frameshift_variant, splice_region_variant	6/11		NP_277043.1
GCK	NM_001354800.1	c.485del	p.Gly162AlafsTer42	frameshift_variant, splice_region_variant	5/11		NP_001341729.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GCK	ENST00000403799.8	c.485del	p.Gly162AlafsTer42	frameshift_variant, splice_region_variant	5/10	1	NM_000162.5	ENSP00000384247	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

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: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152194 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74338

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Maturity onset diabetes mellitus in young Pathogenic:1

Likely pathogenic, 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 rs1246464603 in MODY, yet. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Athena Diagnostics

Aug 30, 2023

This variant is expected to result in the loss of a functional protein. The frequency of this variant in the general population is consistent with pathogenicity (http://gnomad.broadinstitute.org). This variant has been identified in at least one individual with clinical features of MODY. -

Computational scores

Source: dbNSFP v4.3

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: rs1246464603; hg19: chr7-44189661;