rs193922334

Positions:

• chr7-44147647-T-C

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000162.5(GCK):​c.863+3A>G variant causes a splice donor region, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign 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 splice_donor_region, intron
• Scores: Splicing: ADA: 0.9673
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:2 O:1
• Conservation: PhyloP100: 2.61

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 Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GCK	NM_000162.5	c.863+3A>G		splice_donor_region_variant, intron_variant		ENST00000403799.8	NP_000153.1
LOC105375258	XR_927223.3			upstream_gene_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GCK	ENST00000403799.8	c.863+3A>G		splice_donor_region_variant, intron_variant		1	NM_000162.5	ENSP00000384247	P1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:2 Other:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

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

Uncertain risk allele, criteria provided, single submitter	research	Clinical Genomics, Uppaluri K&H Personalized Medicine Clinic	-	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 rs193922334 in MODY, yet. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Dept of Medical Genetics, AP-HP Sorbonne University, Pitié-Salpêtrière hospital	Nov 01, 2022	minigene showed effect on RNA splicing: presence of residual full-length transcripts and an alternative transcript with deletion of the last 10 bp of exon 7 (r.854_863del, p.Gln286Metfs*5). PS3_M PM5 PM2 PP4 -

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

Uncertain significance, criteria provided, single submitter

curation

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Aug 18, 2011

- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Athena Diagnostics

Feb 14, 2019

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.35
CADD	Benign	22
DANN	Benign	0.92

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.97
dbscSNV1_RF	Benign	0.66
SpliceAI score (max)		0.23		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.23		Position offset: 3

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs193922334; hg19: chr7-44187246;