12-21537011-A-G

Variant names:

• chr12-21537011-A-G
• rs201063818
• NM_021957.4:c.2055T>C

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP7

The NM_021957.4(GYS2):​c.2055T>C​(p.Phe685Phe) variant causes a synonymous 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 Uncertain significance (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: GYS2 NM_021957.4 synonymous
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.768
• Publications: 0 publications found

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]

ENSG00000285854 (HGNC:):

SPX (HGNC:28139): (spexin hormone) The protein encoded by this gene is a hormone involved in modulation of cardiovascular and renal function. It has also been shown in rats to cause weight loss. Several transcript variants have been found for this gene. [provided by RefSeq, Feb 2016]

ACMG classification

Our verdict: Likely_benign. The variant received -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.83).
• BP7: Synonymous conserved (PhyloP=0.768 with no splicing effect.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_021957.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GYS2	NM_021957.4	MANE Select	c.2055T>C	p.Phe685Phe	synonymous	Exon 16 of 16	NP_068776.2	P54840

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GYS2	ENST00000261195.3	TSL:1 MANE Select	c.2055T>C	p.Phe685Phe	synonymous	Exon 16 of 16	ENSP00000261195.2	P54840
	ENSG00000285854	ENST00000647960.1		n.*2057T>C		non_coding_transcript_exon	Exon 23 of 23	ENSP00000497202.1	A0A3B3IS95
	ENSG00000285854	ENST00000647960.1		n.*2057T>C		3_prime_UTR	Exon 23 of 23	ENSP00000497202.1	A0A3B3IS95

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251166 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000544

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Uncertain significance

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
-	1	-	Glycogen storage disorder due to hepatic glycogen synthase deficiency (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.83
CADD	Benign	1.1
DANN	Benign	0.55
PhyloP100		0.77

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

Other links and lift over

dbSNP: rs201063818; hg19: chr12-21689945;