7-44150049-A-C

Position:

• chr7-44150049-A-C

Variant summary

Our verdict is Likely pathogenic. Variant got 9 ACMG points: 9P and 0B. PM1 PM2 PP3_Strong PP5

The NM_000162.5(GCK):​c.499T>G​(p.Trp167Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency: Genomes: not found (cov: 33)
• Consequence: GCK NM_000162.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 9.32

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 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a region_of_interest Hexokinase small subdomain (size 136) in uniprot entity HXK4_HUMAN there are 46 pathogenic changes around while only 2 benign (96%) in NM_000162.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.993
• PP5: Variant 7-44150049-A-C is Pathogenic according to our data. Variant chr7-44150049-A-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1314557.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GCK	NM_000162.5	c.499T>G	p.Trp167Gly	missense_variant	5/10	ENST00000403799.8	NP_000153.1
GCK	NM_033507.3	c.502T>G	p.Trp168Gly	missense_variant	5/10		NP_277042.1
GCK	NM_033508.3	c.496T>G	p.Trp166Gly	missense_variant	6/11		NP_277043.1
GCK	NM_001354800.1	c.499T>G	p.Trp167Gly	missense_variant	5/11		NP_001341729.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GCK	ENST00000403799.8	c.499T>G	p.Trp167Gly	missense_variant	5/10	1	NM_000162.5	ENSP00000384247.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000378

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

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 rs1481197092 in MODY, yet. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Nov 23, 2021

Not observed in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Missense variants in this gene are often considered pathogenic (Stenson et al., 2014); Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	33
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.98	.;D;.;.;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.94
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D;.;D;D
M_CAP	Pathogenic	0.91	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Pathogenic	4.1	.;H;.;.;.
PrimateAI	Pathogenic	0.94	D
PROVEAN	Pathogenic	-13	.;D;D;D;D
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0020	.;D;D;D;D
Sift4G	Uncertain	0.0040	D;D;D;D;D
Polyphen		0.98	D;D;D;D;.
Vest4		0.94
MutPred		0.94		.;Loss of stability (P = 0.0092);.;.;.;
MVP		0.95
MPC		2.9
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.99
gMVP		1.0

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: rs1481197092; hg19: chr7-44189648;