chr12-21559650-C-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PVS1_ModeratePM2PP5_Moderate

The NM_021957.4(GYS2):c.1229+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,519,086 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

GYS2
NM_021957.4 splice_donor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 7.79

Variant links:

Genes affected

GYS2 (HGNC:4707): (glycogen synthase 2) The protein encoded by this gene, liver glycogen synthase, catalyzes the rate-limiting step in the synthesis of glycogen - the transfer of a glucose molecule from UDP-glucose to a terminal branch of the glycogen molecule. Mutations in this gene cause glycogen storage disease type 0 (GSD-0) - a rare type of early childhood fasting hypoglycemia with decreased liver glycogen content. [provided by RefSeq, Dec 2009]

GYS2 links:

ENSG00000285854 (HGNC:):

ENSG00000285854 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

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 0.028409092 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 12-21559650-C-T is Pathogenic according to our data. Variant chr12-21559650-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 580790.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	Exon rank	MANE	Protein	UniProt
GYS2	NM_021957.4 link	c.1229+1G>A	splice_donor_variant, intron_variant	Intron 9 of 15	ENST00000261195.3	NP_068776.2	P54840
GYS2	XM_024448960.2 link	c.1229+1G>A	splice_donor_variant, intron_variant	Intron 9 of 16		XP_024304728.1
GYS2	XM_006719063.4 link	c.998+1G>A	splice_donor_variant, intron_variant	Intron 8 of 14		XP_006719126.1
GYS2	XM_017019245.3 link	c.*569G>A	downstream_gene_variant			XP_016874734.1

Ensembl

Gene	Transcript	HGVSc	Effect	Exon rank	TSL	MANE	Protein	UniProt
GYS2	ENST00000261195.3 link	c.1229+1G>A	splice_donor_variant, intron_variant	Intron 9 of 15	1	NM_021957.4	ENSP00000261195.2	P54840
ENSG00000285854	ENST00000647960.1 link	n.*1231+1G>A	splice_donor_variant, intron_variant	Intron 16 of 22			ENSP00000497202.1	A0A3B3IS95
ENSG00000285854	ENST00000648372.1 link	n.1156+1G>A	splice_donor_variant, intron_variant	Intron 9 of 10

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152186

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000797

AC:

AN:

250826

Hom.:

AF XY:

0.00000737

AC XY:

AN XY:

135602

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000124

AC:

AN:

1366900

Hom.:

Cov.:

AF XY:

0.0000146

AC XY:

AN XY:

685690

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.0000224

Gnomad4 ASJ 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:

0.0000156

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152186

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74340

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.000119

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Glycogen storage disorder due to hepatic glycogen synthase deficiency

Pathogenic:1

Aug 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects a donor splice site in intron 9 of the GYS2 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in GYS2 are known to be pathogenic (PMID: 9691087). This variant is present in population databases (rs764539267, gnomAD 0.002%). This variant has not been reported in the literature in individuals affected with GYS2-related conditions. ClinVar contains an entry for this variant (Variation ID: 580790). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.61

BayesDel_noAF

Pathogenic

0.31

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.0

Eigen_PC

Pathogenic

0.81

FATHMM_MKL

Pathogenic

0.97

GERP RS

4.8

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

1.0

Details are displayed if max score is > 0.2

DS_DG_spliceai

0.45

Position offset: -3

DS_DL_spliceai

1.0

Position offset: 1

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over