7-44146541-A-G

Variant names:

• chr7-44146541-A-G
• rs1554334886
• NM_000162.5:c.941T>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.941T>C​(p.Leu314Pro) 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. 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:2 U:1
• Conservation: PhyloP100: 9.16

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 9 ACMG points.

• PM1: In a region_of_interest Hexokinase large subdomain (size 239) in uniprot entity HXK4_HUMAN there are 61 pathogenic changes around while only 2 benign (97%) in NM_000162.5
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.98
• PP5: Variant 7-44146541-A-G is Pathogenic according to our data. Variant chr7-44146541-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 435305.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_risk_allele=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GCK	NM_000162.5	c.941T>C	p.Leu314Pro	missense_variant	Exon 8 of 10	ENST00000403799.8	NP_000153.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GCK	ENST00000403799.8	c.941T>C	p.Leu314Pro	missense_variant	Exon 8 of 10	1	NM_000162.5	ENSP00000384247.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Maturity onset diabetes mellitus in young Pathogenic:1 Uncertain:1

Mar 22, 2019

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.L314P variant (also known as c.941T>C), located in coding exon 8 of the GCK gene, results from a T to C substitution at nucleotide position 941. The leucine at codon 314 is replaced by proline, an amino acid with similar properties. This variant was identified in one individual with a clinical diagnosis of maturity-onset diabetes of the young (Garin I et al. Clin. Endocrinol. (Oxf), 2008 Jun;68:873-8). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on available evidence to date, the clinical significance of this alteration remains unclear. -

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Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic

Significance: Likely risk allele

Review Status: criteria provided, single submitter

Collection Method: research

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 rs1554334886 in MODY, yet. -

Maturity-onset diabetes of the young type 2 Pathogenic:1

Feb 01, 2016

Genetic Services Laboratory, University of Chicago

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.52	D
BayesDel_noAF	Pathogenic	0.51
CADD	Pathogenic	27
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.92	.;D;.;.;.
Eigen	Benign	0.16
Eigen_PC	Uncertain	0.22
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.94	D;D;.;D;D
M_CAP	Pathogenic	0.86	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D
MetaSVM	Pathogenic	0.91	D
MutationAssessor	Uncertain	2.3	.;M;.;.;.
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-5.1	.;D;D;D;D
REVEL	Pathogenic	0.92
Sift	Uncertain	0.0010	.;D;D;D;D
Sift4G	Uncertain	0.011	D;D;D;D;D
Polyphen		0.055	B;B;B;B;.
Vest4		0.96
MutPred		0.88		.;Loss of stability (P = 0.0043);.;.;.;
MVP		0.96
MPC		1.6
ClinPred		0.99	D
GERP RS		4.8
Varity_R		0.98
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: rs1554334886; hg19: chr7-44186140;