2-63841233-G-A

Position:

• chr2-63841233-G-A

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_Strong PM2

The NM_001001521.2(UGP2):​c.-15+1G>A variant causes a splice donor, 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. 2/2 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: UGP2 NM_001001521.2 splice_donor, intron
• Scores: Splicing: ADA: 0.9866
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 2.90

Genes affected

UGP2 (HGNC:12527): (UDP-glucose pyrophosphorylase 2) The enzyme encoded by this gene is an important intermediary in mammalian carbohydrate interconversions. It transfers a glucose moiety from glucose-1-phosphate to MgUTP and forms UDP-glucose and MgPPi. In liver and muscle tissue, UDP-glucose is a direct precursor of glycogen; in lactating mammary gland it is converted to UDP-galactose which is then converted to lactose. The eukaryotic enzyme has no significant sequence similarity to the prokaryotic enzyme. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

UGP2 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.17603749 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
UGP2	NM_001001521.2	c.-15+1G>A		splice_donor_variant, intron_variant			NP_001001521.1
UGP2	NM_001377525.1	c.-76+1G>A		splice_donor_variant, intron_variant			NP_001364454.1
UGP2	NM_001377526.1	c.-511+1G>A		splice_donor_variant, intron_variant			NP_001364455.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
UGP2	ENST00000394417.7	c.-15+1G>A		splice_donor_variant, intron_variant		1		ENSP00000377939.2
UGP2	ENST00000467648.6	c.-76+1G>A		splice_donor_variant, intron_variant		1		ENSP00000420793.2
UGP2	ENST00000613823.2	c.-15+1G>A		splice_donor_variant, intron_variant		5		ENSP00000482043.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0;AS_VQSR AF: 0.00 AC: 0 AN: 112 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 78

Gnomad4 AFR exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Developmental and epileptic encephalopathy, 83 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Institute of Human Genetics, University of Leipzig Medical Center

Dec 20, 2023

Criteria applied: PVS1_MOD,PM2 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.19
CADD	Uncertain	24
DANN	Uncertain	0.99
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	0.99
dbscSNV1_RF	Pathogenic	0.83

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

Publications

LitVar

Other links and lift over

dbSNP: rs993946975; hg19: chr2-64068367;