17-80109993-G-C

Position:

• chr17-80109993-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM2 PM5 PP3_Moderate

The NM_000152.5(GAA):​c.1375G>C​(p.Asp459His) variant causes a missense change. The variant allele was found at a frequency of 0.0000192 in 1,613,198 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. D459N) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 34)
  • Exomes 𝑓: 0.000018 (0 hom.)
• Consequence: GAA NM_000152.5 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:4
• Conservation: PhyloP100: 6.13

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]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-80109993-G-A is described in Lovd as [Likely_pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.92

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
GAA	NM_000152.5	c.1375G>C	p.Asp459His	missense_variant	9/20	ENST00000302262.8	NP_000143.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
GAA	ENST00000302262.8	c.1375G>C	p.Asp459His	missense_variant	9/20	1	NM_000152.5	ENSP00000305692.3

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152260 Hom.: 0 Cov.: 34

Gnomad AFR AF: 0.0000241

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: 0.0000441

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000799 AC: 2 AN: 250268 Hom.: 0 AF XY: 0.00000737 AC XY: 1 AN XY: 135610

Gnomad AFR exome AF: 0.0000622

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000886

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000185 AC: 27 AN: 1460938 Hom.: 0 Cov.: 32 AF XY: 0.0000179 AC XY: 13 AN XY: 726796

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0000225

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152260 Hom.: 0 Cov.: 34 AF XY: 0.0000269 AC XY: 2 AN XY: 74392

Gnomad4 AFR AF: 0.0000241

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000189

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:4

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Glycogen storage disease, type II Pathogenic:1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Sep 05, 2021	- -
Uncertain significance, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 31, 2024	This sequence change replaces aspartic acid, which is acidic and polar, with histidine, which is basic and polar, at codon 459 of the GAA protein (p.Asp459His). This variant is present in population databases (no rsID available, gnomAD 0.007%). This missense change has been observed in individual(s) with Pompe disease (Invitae). ClinVar contains an entry for this variant (Variation ID: 497673). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt GAA protein function with a positive predictive value of 95%. This variant disrupts the p.Asp459 amino acid residue in GAA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 18458862, 21484825, 21757382). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Jul 25, 2023

Variant summary: GAA c.1375G>C (p.Asp459His) results in a non-conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 8e-06 in 250268 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1375G>C has been reported in the literature in at least one compound heterozygous individual affected with Glycogen Storage Disease, Type 2 (Pompe Disease; e.g., Burton_2020) and one infant affected with dilated cardiomyopathy, however without strong evidence for causality (e.g., Langanecha_2023 (Abstract, No PMID)). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 33073003). Four submitters have cited clinical-significance assessments for this variant to ClinVar after 2014; 3 submitters classified the variant as VUS, and one submitter classified the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as uncertain significance. -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Eurofins Ntd Llc (ga)

Oct 10, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.38
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	0.12
CADD	Pathogenic	26
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.92	D;D
Eigen	Uncertain	0.66
Eigen_PC	Uncertain	0.57
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.96	.;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.92	D;D
MetaSVM	Pathogenic	0.92	D
MutationAssessor	Uncertain	2.8	M;M
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-6.3	D;D
REVEL	Pathogenic	0.66
Sift	Uncertain	0.0030	D;D
Sift4G	Uncertain	0.0050	D;D
Polyphen		1.0	D;D
Vest4		0.70
MutPred		0.66		Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);
MVP		1.0
MPC		0.59
ClinPred		0.98	D
GERP RS		5.4
Varity_R		0.82
gMVP		0.86

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: rs535644999; hg19: chr17-78083792; COSMIC: COSV56412684; COSMIC: COSV56412684;