17-80101611-C-T

Variant summary

Our verdict is Benign. Variant got -9 ACMG points: 0P and 9B. BP4_Strong BP6 BS2

The NM_000152.5(GAA):c.-312C>T variant causes a 5 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00157 in 150,922 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

• Frequency:
  • Genomes: 𝑓 0.0016 (2 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: GAA NM_000152.5 5_prime_UTR
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:3
• Conservation: PhyloP100: -0.333

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 Benign. Variant got -9 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.58).
• BP6: Variant 17-80101611-C-T is Benign according to our data. Variant chr17-80101611-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 325768.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=3, Uncertain_significance=1}.
• BS2: High Homozygotes in GnomAd at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
GAA	NM_000152.5	c.-312C>T		5_prime_UTR_variant	1/20	ENST00000302262.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
GAA	ENST00000302262.8	c.-312C>T		5_prime_UTR_variant	1/20	1	NM_000152.5	P1

Frequencies

GnomAD3 genomes AF: 0.00157 AC: 237 AN: 150814 Hom.: 2 Cov.: 32

Gnomad AFR AF: 0.000485

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00251

Gnomad ASJ AF: 0.000577

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.000207

Gnomad FIN AF: 0.000394

Gnomad MID AF: 0.0127

Gnomad NFE AF: 0.00244

Gnomad OTH AF: 0.00145

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 20 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 10

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00157 AC: 237 AN: 150922 Hom.: 2 Cov.: 32 AF XY: 0.00149 AC XY: 110 AN XY: 73760

Gnomad4 AFR AF: 0.000484

Gnomad4 AMR AF: 0.00250

Gnomad4 ASJ AF: 0.000577

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.000208

Gnomad4 FIN AF: 0.000394

Gnomad4 NFE AF: 0.00244

Gnomad4 OTH AF: 0.00143

Alfa AF: 0.00148 Hom.: 0

Bravo AF: 0.00156

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:3

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Glycogen storage disease, type II Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	curation	Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard	Jan 22, 2020	The c.-312C>T variant in GAA has not been previously reported in individuals with Glycogen Storage Disease II but has been reported as a VUS by Illumina and as a likely benign variant by GeneDx in ClinVar (Variation ID: 325768). This variant has been identified in 0.209% (31/14830) of European (non-Finnish) chromosomes and other populations at lesser frequencies by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs574326920). Although this variant has been seen in the general population, its frequency is not high enough to rule out a pathogenic role. Computational prediction tools and conservation analyses suggest that this 5' UTR variant may not impact the protein, though this information is not predictive enough to rule out pathogenicity. In summary, although additional studies are required to fully establish its clinical significance, this variant is likely benign. ACMG/AMP Criteria applied: BP4, BP7 (Richards 2015). -
Uncertain significance, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Jan 13, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score, this variant could not be ruled out of causing disease and therefore its association with disease required further investigation. A literature search was performed for the gene, cDNA change, and amino acid change (if applicable). No publications were found based on this search. This variant was therefore classified as a variant of unknown significance for this disease. -

not specified Benign:1

Likely benign, criteria provided, single submitter

clinical testing

GeneDx

Dec 22, 2017

This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

GAA-related disorder Benign:1

Likely benign, criteria provided, single submitter

clinical testing

PreventionGenetics, part of Exact Sciences

Feb 23, 2022

This variant is classified as likely benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.58
Cadd	Benign	15
Dann	Benign	0.97
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.050		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: rs574326920; hg19: chr17-78075410;