17-80104704-C-T

Variant names:

• chr17-80104704-C-T
• rs767409395
• NM_000152.5:c.118C>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PP4 PM3_Supporting PM2 PVS1

This summary comes from the ClinGen Evidence Repository: This nonsense variant, c.118C>T (p.Arg40Ter), is expected to result in a premature termination codon, nonsense mediated decay, and absence of gene product, meeting PVS1. The highest population minor allele frequency in gnomAD v2.1.1 is 0.00007 in the South Asian population, meeting PM2. The variant was found in compound heterozygosity with c.-32-13T>G, phase unknown, in two patients with Pompe disease who also meet the ClinGen LSD VCEP's PP4 criterion (PMID 22676651, 22958975), meeting PM3_Supporting. In addition, a large family has been reported with 7 affected siblings who are compound heterozygous for the variant and a variant of unknown significance, c.2647-7G>A (PMID 24107549). Additional cases with this variant have been reported but were not included because residual enzyme activity was not provided and therefore PP4 could not be assessed. There is a ClinVar entry for this variant (Variation ID: 426593, 2 star review status) with two submitters classifying the variant as pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. GAA-specific ACMG/AMP criteria applied, as specified by the ClinGen LSD VCEP: PVS1, PM2, PM3_Supporting, PP4. LINK:https://erepo.genome.network/evrepo/ui/classification/CA8814791/MONDO:0009290/010

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000015 (0 hom.)
• Consequence: GAA NM_000152.5 stop_gained
• Clinical Significance: Pathogenic reviewed by expert panel P:11
• Conservation: PhyloP100: 1.40
• Publications: 12 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: Pathogenic. The variant received 12 ACMG points.

• PVS1: For more information check the summary or visit ClinGen Evidence Repository.
• PM2: For more information check the summary or visit ClinGen Evidence Repository.
• PM3: For more information check the summary or visit ClinGen Evidence Repository.
• PP4: For more information check the summary or visit ClinGen Evidence Repository.

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.118C>T	p.Arg40*	stop_gained	Exon 2 of 20	NP_000143.2
	GAA	NM_001079803.3		c.118C>T	p.Arg40*	stop_gained	Exon 3 of 21	NP_001073271.1
	GAA	NM_001079804.3		c.118C>T	p.Arg40*	stop_gained	Exon 2 of 20	NP_001073272.1

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	GAA	ENST00000302262.8	TSL:1 MANE Select	c.118C>T	p.Arg40*	stop_gained	Exon 2 of 20	ENSP00000305692.3
	GAA	ENST00000390015.7	TSL:1	c.118C>T	p.Arg40*	stop_gained	Exon 3 of 21	ENSP00000374665.3
	GAA	ENST00000933406.1		c.118C>T	p.Arg40*	stop_gained	Exon 2 of 20	ENSP00000603465.1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152150 Hom.: 0 Cov.: 32

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: 0.0000121 AC: 3 AN: 248728 AF XY: 0.0000222

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000545

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000151 AC: 22 AN: 1460770 Hom.: 0 Cov.: 31 AF XY: 0.0000179 AC XY: 13 AN XY: 726686

African (AFR) AF: 0.00 AC: 0 AN: 33472

American (AMR) AF: 0.0000224 AC: 1 AN: 44688

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39690

South Asian (SAS) AF: 0.0000464 AC: 4 AN: 86170

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52628

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.0000153 AC: 17 AN: 1111870

Other (OTH) AF: 0.00 AC: 0 AN: 60366

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152268 Hom.: 0 Cov.: 32 AF XY: 0.0000134 AC XY: 1 AN XY: 74454

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

African (AFR) AF: 0.00 AC: 0 AN: 41562

American (AMR) AF: 0.00 AC: 0 AN: 15304

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3462

East Asian (EAS) AF: 0.00 AC: 0 AN: 5180

South Asian (SAS) AF: 0.00 AC: 0 AN: 4822

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10620

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 67998

Other (OTH) AF: 0.00 AC: 0 AN: 2114

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

Alfa AF: 0.000288 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

ClinVar submissions as Germline

Significance: Pathogenic

Revision: reviewed by expert panel

Pathogenic	VUS	Benign	Condition
9	-	-	Glycogen storage disease, type II (9)
2	-	-	not provided (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.29
CADD	Pathogenic	35
DANN	Uncertain	1.0
Eigen	Uncertain	0.40
Eigen_PC	Benign	0.14
FATHMM_MKL	Benign	0.083	N
PhyloP100		1.4
Vest4		0.63
GERP RS		3.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Mutation Taster		=0/200	disease causing (ClinVar)

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: rs767409395; hg19: chr17-78078503;