rs766733439

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1PM2PP5_Moderate

The NM_021957.4(GYS2):​c.1230-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000818 in 1,589,064 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: 32)
Exomes 𝑓: 0.0000083 ( 0 hom. )

Consequence

GYS2
NM_021957.4 splice_acceptor, intron

Scores

5
1
1
Splicing: ADA: 1.000
2

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 7.68

Publications

0 publications found
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 Gene-Disease associations (from GenCC):
  • glycogen storage disorder due to hepatic glycogen synthase deficiency
    Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, PanelApp Australia, Genomics England PanelApp, Labcorp Genetics (formerly Invitae)

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 12 ACMG points.

PVS1
Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 5.5, offset of 2, new splice context is: aacattttttccctgcaaAGgag. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 12-21559170-C-T is Pathogenic according to our data. Variant chr12-21559170-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 402231.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
GYS2NM_021957.4 linkc.1230-1G>A splice_acceptor_variant, intron_variant Intron 9 of 15 ENST00000261195.3 NP_068776.2 P54840
GYS2XM_024448960.2 linkc.1230-1G>A splice_acceptor_variant, intron_variant Intron 9 of 16 XP_024304728.1
GYS2XM_006719063.4 linkc.999-1G>A splice_acceptor_variant, intron_variant Intron 8 of 14 XP_006719126.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
GYS2ENST00000261195.3 linkc.1230-1G>A splice_acceptor_variant, intron_variant Intron 9 of 15 1 NM_021957.4 ENSP00000261195.2 P54840
ENSG00000285854ENST00000647960.1 linkn.*1232-1G>A splice_acceptor_variant, intron_variant Intron 16 of 22 ENSP00000497202.1 A0A3B3IS95
ENSG00000285854ENST00000648372.1 linkn.1157-1G>A splice_acceptor_variant, intron_variant Intron 9 of 10

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
151932
Hom.:
0
Cov.:
32
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
GnomAD2 exomes
AF:
0.0000200
AC:
5
AN:
250336
AF XY:
0.0000295
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000441
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000835
AC:
12
AN:
1437132
Hom.:
0
Cov.:
25
AF XY:
0.0000126
AC XY:
9
AN XY:
716462
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
32916
American (AMR)
AF:
0.00
AC:
0
AN:
44590
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25920
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39340
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85386
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53208
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5690
European-Non Finnish (NFE)
AF:
0.0000110
AC:
12
AN:
1090584
Other (OTH)
AF:
0.00
AC:
0
AN:
59498
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.467
Heterozygous variant carriers
0
1
2
4
5
6
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000658
AC:
1
AN:
151932
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74202
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41382
American (AMR)
AF:
0.00
AC:
0
AN:
15258
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10506
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
67974
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000675
Hom.:
0
Bravo
AF:
0.0000113
ExAC
AF:
0.0000165
AC:
2

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
Jul 24, 2015
Knight Diagnostic Laboratories, Oregon Health and Sciences University
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is predicted to affect the splice-acceptor site in intron 9 of the GYS2 gene. The frequency of this variant is very low in the ExAC database and is absent in both the 1000 Genomes and Exome Sequencing Project databases. In addition, splice-site computational algorithms have predicted this variant to abrogate splicing. Loss-of-function mutations are a known mechanism of disease for this disorder; therefore, we have provisionally classified this variant as Likely Pathogenic. We have confirmed this sequence change in our laboratory using Sanger sequencing. However, splicing studies are necessary to confirm this interpretation. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.58
D
BayesDel_noAF
Pathogenic
0.39
CADD
Pathogenic
35
DANN
Uncertain
1.0
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
0.96
FATHMM_MKL
Pathogenic
0.99
D
PhyloP100
7.7
GERP RS
4.8
Mutation Taster
=0/100
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.94
SpliceAI score (max)
0.99
Details are displayed if max score is > 0.2
DS_AG_spliceai
0.87
Position offset: -3
DS_AL_spliceai
0.99
Position offset: -1

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

Publications

Other links and lift over

dbSNP: rs766733439; hg19: chr12-21712104; API