7-44150049-A-G

Variant names:

• chr7-44150049-A-G
• rs1481197092
• NM_000162.5:c.499T>C

Variant summary

Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1 PM2 PM5 PP2 PP3_Strong

The NM_000162.5(GCK):​c.499T>C​(p.Trp167Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000131 in 152,152 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W167G) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.000013 (0 hom., cov: 33)
• Consequence: GCK NM_000162.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.32
• Publications: 5 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: Labcorp Genetics (formerly Invitae), Genomics England PanelApp, Ambry Genetics
• 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

Our verdict: Pathogenic. The variant received 11 ACMG points.

• PM1: In a hotspot region, there are 20 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 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 chr7-44150047-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 1685845.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 274 curated pathogenic missense variants (we use a threshold of 10). The gene has 10 curated benign missense variants. Gene score misZ: 3.069 (below the threshold of 3.09). Trascript score misZ: 2.7821 (below the threshold of 3.09). GenCC associations: The gene is linked to transient neonatal diabetes mellitus, monogenic diabetes, permanent neonatal diabetes mellitus 1, diabetes mellitus, noninsulin-dependent, maturity-onset diabetes of the young type 2, hyperinsulinism due to glucokinase deficiency, permanent neonatal diabetes mellitus, maturity-onset diabetes of the young.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.994

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

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GCK	NM_000162.5	MANE Select	c.499T>C	p.Trp167Arg	missense	Exon 5 of 10	NP_000153.1
	GCK	NM_033507.3		c.502T>C	p.Trp168Arg	missense	Exon 5 of 10	NP_277042.1
	GCK	NM_033508.3		c.496T>C	p.Trp166Arg	missense	Exon 6 of 11	NP_277043.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GCK	ENST00000403799.8	TSL:1 MANE Select	c.499T>C	p.Trp167Arg	missense	Exon 5 of 10	ENSP00000384247.3
	GCK	ENST00000395796.8	TSL:1	n.*497T>C		non_coding_transcript_exon	Exon 6 of 11	ENSP00000379142.4
	GCK	ENST00000395796.8	TSL:1	n.*497T>C		3_prime_UTR	Exon 6 of 11	ENSP00000379142.4

Frequencies

GnomAD3 genomes AF: 0.0000131 AC: 2 AN: 152152 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.000576

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD4 exome Cov.: 33

GnomAD4 genome AF: 0.0000131 AC: 2 AN: 152152 Hom.: 0 Cov.: 33 AF XY: 0.0000269 AC XY: 2 AN XY: 74334

African (AFR) AF: 0.00 AC: 0 AN: 41426

American (AMR) AF: 0.00 AC: 0 AN: 15280

Ashkenazi Jewish (ASJ) AF: 0.000576 AC: 2 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5192

South Asian (SAS) AF: 0.00 AC: 0 AN: 4830

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10610

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 68024

Other (OTH) AF: 0.00 AC: 0 AN: 2092

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

May 01, 2017

Athena Diagnostics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

not provided Uncertain:1

Jul 31, 2017

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The W167R variant has been published previously in association with MODY (Gozlan et al., 2012). The variant is not observed in large population cohorts (Lek et al., 2016; 1000 Genomes Consortium et al., 2015; Exome Variant Server). W167R is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. This substitution occurs at a position that is conserved across species, and in silico analysis predicts this variant is probably damaging to the protein structure/function. In summary, based on the currently available information, it is unclear whether this variant is a pathogenic variant or a rare benign variant.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.56
CADD	Pathogenic	30
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.98	D
Eigen	Pathogenic	0.89
Eigen_PC	Pathogenic	0.85
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	D
M_CAP	Pathogenic	0.84	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Pathogenic	4.1	H
PhyloP100		9.3
PrimateAI	Pathogenic	0.96	D
PROVEAN	Pathogenic	-14	D
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0050	D
Sift4G	Uncertain	0.0080	D
Polyphen		0.93	P
Vest4		0.99
MutPred		0.96		Gain of disorder (P = 0.0226)
MVP		0.98
MPC		2.8
ClinPred		1.0	D
GERP RS		5.7
Varity_R		0.98
gMVP		1.0
Mutation Taster		=0/100	disease causing

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: rs1481197092; hg19: chr7-44189648;