rs1360415315

chr7-44149772-C-Gchr7-44149772-C-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_000162.5(GCK):c.667G>C(p.Gly223Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,720 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G223S) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: GCK NM_000162.5 missense
• Clinical Significance: 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]

LOC105375258 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_000162.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr7-44149772-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 435306.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.995
• PP5: Variant 7-44149772-C-G is Pathogenic according to our data. Variant chr7-44149772-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2578075.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GCK	NM_000162.5	c.667G>C	p.Gly223Arg	missense_variant	6/10	ENST00000403799.8
LOC105375258	XR_927223.3	n.303C>G		non_coding_transcript_exon_variant	3/3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GCK	ENST00000403799.8	c.667G>C	p.Gly223Arg	missense_variant	6/10	1	NM_000162.5	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251410 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135906

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.0000992

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461720 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 727162

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.0000383

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 13, 2023	This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 223 of the GCK protein (p.Gly223Arg). This variant is present in population databases (no rsID available, gnomAD 0.01%). This missense change has been observed in individuals with clinical features of autosomal dominant maturity onset diabetes of the young (PMID: 19790256; Invitae). ClinVar contains an entry for this variant (Variation ID: 2578075). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GCK protein function with a positive predictive value of 80%. This variant disrupts the p.Gly223 amino acid residue in GCK. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 21437567, 31216263, 32041611, 33294763, 33565752). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Mar 01, 2023	Reported in association with MODY in published literature (Osbak et al., 2009); however, no patient clinical information was provided; Not observed at significant frequency in large population cohorts (gnomAD); Missense variants in this gene are often considered pathogenic (HGMD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 19790256) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.57	D
BayesDel_noAF	Pathogenic	0.58
Cadd	Pathogenic	30
Dann	Pathogenic	1.0
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Pathogenic	1.0	D;D;.;D;D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Pathogenic	0.83	D
Sift4G	Pathogenic	0.0	D;D;D;D;D
Polyphen		1.0	D;D;D;D;.
Vest4		0.99
MutPred		0.98		.;Loss of catalytic residue at I225 (P = 0.1937);.;.;.;
MVP		0.98
MPC		2.4
ClinPred		1.0	D
GERP RS		6.2
Varity_R		0.99
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs1360415315; hg19: chr7-44189371;