12-21558286-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_021957.4(GYS2):c.1336C>A(p.His446Asn) 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H446D) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GYS2 NM_021957.4 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.90

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.939

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GYS2	NM_021957.4	c.1336C>A	p.His446Asn	missense_variant	11/16	ENST00000261195.3
GYS2	XM_024448960.2	c.1336C>A	p.His446Asn	missense_variant	11/17
GYS2	XM_006719063.4	c.1105C>A	p.His369Asn	missense_variant	10/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GYS2	ENST00000261195.3	c.1336C>A	p.His446Asn	missense_variant	11/16	1	NM_021957.4	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.95
BayesDel_addAF	Uncertain	0.14	D
BayesDel_noAF	Uncertain	-0.040
Cadd	Pathogenic	29
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.78	D
Eigen	Pathogenic	0.99
Eigen_PC	Pathogenic	0.89
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D
M_CAP	Uncertain	0.10	D
MetaRNN	Pathogenic	0.94	D
MetaSVM	Uncertain	0.53	D
MutationAssessor	Pathogenic	3.5	M
MutationTaster	Benign	1.0	D
PrimateAI	Pathogenic	0.84	D
PROVEAN	Pathogenic	-6.9	D
REVEL	Pathogenic	0.72
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0010	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.77		Gain of catalytic residue at P441 (P = 0.001);
MVP		0.93
MPC		0.59
ClinPred		1.0	D
GERP RS		4.5
Varity_R		0.90
gMVP		0.91

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs121918425; hg19: chr12-21711220; COSMIC: COSV53927357;