chr7-44145594-GC-G

Variant names:

• chr7-44145594-GC-G
• rs1400535021
• NM_000162.5:c.1155delG

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000162.5(GCK):​c.1155delG​(p.Leu386TrpfsTer16) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000688 in 1,453,800 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★★). Synonymous variant affecting the same amino acid position (i.e. G385G) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay. The gene GCK is included in the ClinGen Criteria Specification Registry.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GCK NM_000162.5 frameshift
• Clinical Significance: Pathogenic reviewed by expert panel P:7 O:1
• Conservation: PhyloP100: -0.317
• Publications: 2 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: Ambry Genetics, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• 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

ENSG00000300758 (HGNC:):

ACMG classification

Specifications for GCK are available in the ClinGen Criteria Specification Registry and recommended for reference when assigning criteria.

Our verdict: Pathogenic. The variant received 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 7-44145594-GC-G is Pathogenic according to our data. Variant chr7-44145594-GC-G is described in ClinVar as Pathogenic. ClinVar VariationId is 503699.Status of the report is reviewed_by_expert_panel, 3 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000162.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GCK	NM_000162.5	MANE Select	c.1155delG	p.Leu386TrpfsTer16	frameshift	Exon 9 of 10	NP_000153.1	Q53Y25
	GCK	NM_033507.3		c.1158delG	p.Leu387TrpfsTer16	frameshift	Exon 9 of 10	NP_277042.1	P35557-2
	GCK	NM_033508.3		c.1152delG	p.Leu385TrpfsTer16	frameshift	Exon 10 of 11	NP_277043.1	P35557-3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GCK	ENST00000403799.8	TSL:1 MANE Select	c.1155delG	p.Leu386TrpfsTer16	frameshift	Exon 9 of 10	ENSP00000384247.3	P35557-1
	GCK	ENST00000395796.8	TSL:1	n.*1153delG		non_coding_transcript_exon	Exon 10 of 11	ENSP00000379142.4	A0A8C8KJG0
	GCK	ENST00000459642.1	TSL:1	n.535delG		non_coding_transcript_exon	Exon 1 of 2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD2 exomes AF: 0.00000431 AC: 1 AN: 231862 AF XY: 0.00000788

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.000174

GnomAD4 exome AF: 6.88e-7 AC: 1 AN: 1453800 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 723084

African (AFR) AF: 0.00 AC: 0 AN: 33380

American (AMR) AF: 0.00 AC: 0 AN: 44156

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26012

East Asian (EAS) AF: 0.00 AC: 0 AN: 39482

South Asian (SAS) AF: 0.00 AC: 0 AN: 85498

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 49438

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5746

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109994

Other (OTH) AF: 0.0000166 AC: 1 AN: 60094

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
2	-	-	not provided (2)
1	-	-	Hyperinsulinism due to glucokinase deficiency (1)
-	1	-	Maturity-onset diabetes of the young (1)
1	-	-	Maturity-onset diabetes of the young type 2 (1)
1	-	-	Monogenic diabetes (1)
1	-	-	Permanent neonatal diabetes mellitus 1 (1)
1	-	-	Type 2 diabetes mellitus (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		-0.32
Mutation Taster		=0/200	disease causing (ClinVar)

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: rs1400535021; hg19: chr7-44185193;