17-80105857-G-T

Variant names:

• chr17-80105857-G-T
• rs370950728
• NM_000152.5:c.655G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate

The NM_000152.5(GAA):​c.655G>T​(p.Gly219Trp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000688 in 1,453,526 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G219R) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: GAA NM_000152.5 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 9.71
• Publications: 0 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, ClinGen, Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine
• 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: Likely_pathogenic. The variant received 9 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 11 uncertain in NM_000152.5
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-80105857-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 189065.Status of the report is reviewed_by_expert_panel, 3 stars.
• 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 II, glycogen storage disease due to acid maltase deficiency, infantile onset, glycogen storage disease due to acid maltase deficiency, late-onset.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.918

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000152.5. 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
	GAA	NM_000152.5	MANE Select	c.655G>T	p.Gly219Trp	missense	Exon 3 of 20	NP_000143.2	P10253
	GAA	NM_001079803.3		c.655G>T	p.Gly219Trp	missense	Exon 4 of 21	NP_001073271.1	P10253
	GAA	NM_001079804.3		c.655G>T	p.Gly219Trp	missense	Exon 3 of 20	NP_001073272.1	P10253

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	ENST00000302262.8	TSL:1 MANE Select	c.655G>T	p.Gly219Trp	missense	Exon 3 of 20	ENSP00000305692.3	P10253
	GAA	ENST00000390015.7	TSL:1	c.655G>T	p.Gly219Trp	missense	Exon 4 of 21	ENSP00000374665.3	P10253
	GAA	ENST00000714054.1		c.-147G>T		5_prime_UTR_premature_start_codon_gain	Exon 2 of 19	ENSP00000519344.1	A0AAQ5BHE1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome AF: 6.88e-7 AC: 1 AN: 1453526 Hom.: 0 Cov.: 57 AF XY: 0.00 AC XY: 0 AN XY: 723044

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33444

American (AMR) AF: 0.00 AC: 0 AN: 44704

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26112

East Asian (EAS) AF: 0.00 AC: 0 AN: 39662

South Asian (SAS) AF: 0.00 AC: 0 AN: 86224

European-Finnish (FIN) AF: 0.0000213 AC: 1 AN: 47046

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5444

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1110638

Other (OTH) AF: 0.00 AC: 0 AN: 60252

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.33	D
BayesDel_noAF	Pathogenic	0.24
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.72	D
Eigen	Pathogenic	0.80
Eigen_PC	Pathogenic	0.69
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.61	D
MetaRNN	Pathogenic	0.92	D
MetaSVM	Uncertain	0.77	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		9.7
PrimateAI	Uncertain	0.58	T
PROVEAN	Pathogenic	-6.8	D
REVEL	Pathogenic	0.79
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.86
MutPred		0.56		Loss of disorder (P = 0.0597)
MVP		0.97
MPC		0.50
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.91
gMVP		0.92

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: rs370950728; hg19: chr17-78079656;