7-44145170-A-G

Variant names:

• chr7-44145170-A-G
• rs753795627
• NM_000162.5:c.1364T>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.1364T>C​(p.Val455Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000137 in 1,457,460 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V455E) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: GCK NM_000162.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 4.82
• Publications: 0 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

ACMG classification

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

• PM1: In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 2 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 chr7-44145170-A-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 585916.
• 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, 0.967

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.1364T>C	p.Val455Ala	missense	Exon 10 of 10	NP_000153.1	Q53Y25
	GCK	NM_033507.3		c.1367T>C	p.Val456Ala	missense	Exon 10 of 10	NP_277042.1	P35557-2
	GCK	NM_033508.3		c.1361T>C	p.Val454Ala	missense	Exon 11 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.1364T>C	p.Val455Ala	missense	Exon 10 of 10	ENSP00000384247.3	P35557-1
	GCK	ENST00000395796.8	TSL:1	n.*1362T>C		non_coding_transcript_exon	Exon 11 of 11	ENSP00000379142.4	A0A8C8KJG0
	GCK	ENST00000459642.1	TSL:1	n.744T>C		non_coding_transcript_exon	Exon 2 of 2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1457460 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 724990

African (AFR) AF: 0.00 AC: 0 AN: 33444

American (AMR) AF: 0.00 AC: 0 AN: 44524

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26056

East Asian (EAS) AF: 0.00 AC: 0 AN: 39620

South Asian (SAS) AF: 0.00 AC: 0 AN: 85838

European-Finnish (FIN) AF: 0.0000196 AC: 1 AN: 50912

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5754

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111112

Other (OTH) AF: 0.00 AC: 0 AN: 60200

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.48
BayesDel_addAF	Pathogenic	0.36	D
BayesDel_noAF	Pathogenic	0.28
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.52	D
Eigen	Uncertain	0.50
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.82	T
M_CAP	Pathogenic	0.42	D
MetaRNN	Pathogenic	0.97	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.1	M
PhyloP100		4.8
PrimateAI	Uncertain	0.66	T
PROVEAN	Uncertain	-3.8	D
REVEL	Pathogenic	0.85
Sift	Uncertain	0.0010	D
Sift4G	Uncertain	0.034	D
Polyphen		0.99	D
Vest4		0.35
MutPred		0.87		Gain of disorder (P = 0.0188)
MVP		0.96
MPC		1.4
ClinPred		0.99	D
GERP RS		5.8
Varity_R		0.91
gMVP		0.96
Mutation Taster		=4/96	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: rs753795627; hg19: chr7-44184769;