NM_000152.5:c.2609G>C

Variant names:

• chr17-80118320-G-C
• rs747076541
• NM_000152.5:c.2609G>C

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2 PP2

The NM_000152.5(GAA):​c.2609G>C​(p.Arg870Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R870Q) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: GAA NM_000152.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.390
• Publications: 4 publications found

Genes affected

GAA (HGNC:4065): (alpha glucosidase) This gene encodes lysosomal alpha-glucosidase, which is essential for the degradation of glycogen to glucose in lysosomes. The encoded preproprotein is proteolytically processed to generate multiple intermediate forms and the mature form of the enzyme. Defects in this gene are the cause of glycogen storage disease II, also known as Pompe's disease, which is an autosomal recessive disorder with a broad clinical spectrum. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2016]

GAA Gene-Disease associations (from GenCC):

• glycogen storage disease II

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Genomics England PanelApp, Laboratory for Molecular Medicine, Labcorp Genetics (formerly Invitae), PanelApp Australia, ClinGen, G2P
• glycogen storage disease due to acid maltase deficiency, infantile onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• glycogen storage disease due to acid maltase deficiency, late-onset

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 201 curated pathogenic missense variants (we use a threshold of 10). The gene has 50 curated benign missense variants. Gene score misZ: -0.63308 (below the threshold of 3.09). Trascript score misZ: -0.32889 (below the threshold of 3.09). GenCC associations: The gene is linked to glycogen storage disease due to acid maltase deficiency, infantile onset, glycogen storage disease II, glycogen storage disease due to acid maltase deficiency, late-onset.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
GAA	NM_000152.5	c.2609G>C	p.Arg870Pro	missense_variant	Exon 18 of 20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8	c.2609G>C	p.Arg870Pro	missense_variant	Exon 18 of 20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Cardiovascular phenotype Uncertain:1

Jun 28, 2023

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R870P variant (also known as c.2609G>C), located in coding exon 17 of the GAA gene, results from a G to C substitution at nucleotide position 2609. The arginine at codon 870 is replaced by proline, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.20
BayesDel_addAF	Uncertain	0.052	T
BayesDel_noAF	Benign	-0.16
CADD	Benign	12
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.69	D;D
Eigen	Benign	-0.48
Eigen_PC	Benign	-0.57
FATHMM_MKL	Benign	0.14	N
LIST_S2	Benign	0.67	.;T
M_CAP	Uncertain	0.21	D
MetaRNN	Uncertain	0.44	T;T
MetaSVM	Benign	-0.40	T
MutationAssessor	Benign	1.7	L;L
PhyloP100		-0.39
PrimateAI	Benign	0.22	T
PROVEAN	Uncertain	-2.6	D;D
REVEL	Uncertain	0.39
Sift	Benign	0.10	T;T
Sift4G	Benign	0.20	T;T
Polyphen		0.68	P;P
Vest4		0.48
MutPred		0.42		Loss of solvent accessibility (P = 0.0703);Loss of solvent accessibility (P = 0.0703);
MVP		0.96
MPC		0.16
ClinPred		0.43	T
GERP RS		1.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.76
gMVP		0.94

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: rs747076541; hg19: chr17-78092119;