chr7-44147732-C-G
Variant summary
Our verdict is Pathogenic. Variant got 26 ACMG points: 26P and 0B. PS1_Very_StrongPM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_000162.5(GCK):c.781G>C(p.Gly261Arg) 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 Pathogenic (★★★). Another nucleotide change resulting in same amino acid change has been previously reported as Pathogenicin ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G261E) has been classified as Pathogenic.
Frequency
Consequence
NM_000162.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 26 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
GCK | NM_000162.5 | c.781G>C | p.Gly261Arg | missense_variant | 7/10 | ENST00000403799.8 | |
LOC105375258 | XR_927223.3 | n.82C>G | non_coding_transcript_exon_variant | 1/3 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
GCK | ENST00000403799.8 | c.781G>C | p.Gly261Arg | missense_variant | 7/10 | 1 | NM_000162.5 | P1 |
Frequencies
GnomAD3 genomes ? Cov.: 33
GnomAD4 exome Cov.: 32
GnomAD4 genome ? Cov.: 33
ClinVar
Submissions by phenotype
not provided Pathogenic:2
Pathogenic, criteria provided, single submitter | clinical testing | Invitae | Oct 28, 2023 | This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 261 of the GCK protein (p.Gly261Arg). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with autosomal dominant maturity onset diabetes of the young (PMID: 1502186, 30592380, 31291970, 36227502). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 447418). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on GCK protein function. Experimental studies have shown that this missense change affects GCK function (PMID: 10525657). For these reasons, this variant has been classified as Pathogenic. - |
Pathogenic, criteria provided, single submitter | clinical testing | Athena Diagnostics | Aug 17, 2016 | - - |
Monogenic diabetes Pathogenic:1
Pathogenic, reviewed by expert panel | curation | ClinGen Monogenic Diabetes Variant Curation Expert Panel | Aug 12, 2023 | The c.781G>C variant in the glucokinase gene, GCK, causes an amino acid change of glycine to arginine at codon 261 (p.(Gly261Arg)) of NM_000162.5. GCK is defined by the ClinGen MDEP as a gene that has a low rate of benign missense variation and has pathogenic missense variants as a common mechanism of disease (PP2). This variant is predicted to be deleterious by computational evidence, with a REVEL score of 0.914, which is greater than the MDEP threshold of 0.70 (PP3). This variant was identified in an individual with a clinical history highly specific for GCK-hyperglycemia (FBG 5.5-8 mmol/L and HbA1c 5.6 - 7.6% and negative antibodies) (PP4_Moderate; internal lab contributors). This variant segregated with hyperglycemia with one informative meioses in a single family; however, this does not meet the thresholds for PP1 set by the ClinGen MDEP (PMID: 27236918, internal lab contributors). This variant was identified in 5 unrelated individuals with hyperglycemia (PS4_Moderate; internal lab contributors). The nucleotide change c.781G>A, which causes the same amino acid change, has been classified as pathogenic by the ClinGen MDEP (PS1). A kinetic analysis of recombinant wild-type (WT) and mutant glucokinase demonstrated that the wild-type kinetic parameters pass the quality control, the wild-type ATP Km is between 0.4-0.65, and the p.Gly261Arg variant has a relative activity index (RAI) of 0.02, which is less than the MDEP VCEP threshold of 0.50 (PMID: 19903754). In summary, the c.781G>C variant meets the criteria to be classified as pathogenic for monogenic diabetes. ACMG/AMP criteria applied, as specified by the ClinGen MDEP VCEP (specification version 1.3.0, approved 8/11/2023): PM2_Supporting, PP2, PP3, PS3_Moderate, PS1, PS4_Moderate, PP4_Moderate. - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at