rs786204459
Variant summary
Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PP4_ModeratePM3_StrongPM5_SupportingPS3_SupportingPP3PM2_Supporting
This summary comes from the ClinGen Evidence Repository: The NM_000152.5:c.2014C>T variant in GAA is a missense variant predicted to cause substitution of arginine by tryptophan at amino acid 672 (p.Arg672Trp). The variant has been reported in 5 patients with a diagnosis of Pompe disease supported by <10% normal GAA activity in muscle (PMID 9535769), <1% GAA activity in cultured fibroblasts (PMID 16917947), or GAA activity in the affected range in leukocytes or lymphocytes (PMID 22676651, 25526786) in addition to at least 5 patients stated to have symptoms consistent with Pompe disease and deficient GAA activity but values not provided (PMID 16917947, 21803581, 27692865)(PP4_Moderate). At least 5 patients are compound heterozygous for the variant and a variant in GAA classified as pathogenic by the ClinGen LSD VCEP, phase unknown - c.-32-13T>G (PMID 16917947), c.2385delG (PMID 21484825), c.1411_1414del (PMID 27692865), c.766_785delinsC (PMID 9535769), and c.1951_1952insT (clinical laboratory data) (PM3_Strong). The variant has also been reported in compound heterozygotes with c.1748C>T(p.Ser583Phe)(PMID 21484825), c.323G>A (p.Cys108Tyr) (PMID 25526786), c.1465G>A (p.Asp489Asn)(PMID 16917947), c.1703A>T (p.His568Leu)(PMID 17027861, 22676651), c.2474C>G (p.Pro825Arg)(PMID 30564623). The in trans data from these patients will be used in the assessment of the second variant and is not included here in order to avoid circular logic. The highest population minor allele frequency in gnomAD v2.1.1 is 0.00003 (1/29806 alleles) in the South Asian population, which is lower than the ClinGen LSD VCEP’s threshold for PM2_Supporting (<0.001), meeting this criterion (PM2_Supporting). Expression of the variant in SV40-immortalized GAA-deficient fibroblasts revealed activity of <1% of the control value (PMID 9535769), and <2% activity in COS cells (PMID 19862843) (PS3_Supporting). The computational predictor REVEL gives a score of 0.9 which is above the threshold of 0.7, evidence that correlates with impact to GAA function (PP3). Another missense variant c.2015G>A (p.Arg672Gln)(see Table 1 in PMID 33578445) in the same codon has been classified as pathogenic for Pompe disease by the ClinGen LSD VCEP (likely pathogenic without PM5 data from c.2014C>T (p.Arg672Trp) PM5_Supporting). c.2015G>T (p.Arg672Leu) has also been reported but has not yet met the criteria to be classified as pathogenic or likely pathogenic. There is a ClinVar entry for this variant (Variation ID: 188773; 2 star status) with 5 submitters classifying the variant as pathogenic and one as likely pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. ACMG/AMP criteria met, as specified by the ClinGen Lysosomal Storage Disorders VCEP: PM3_Strong, PP4_Moderate, PP3, PS3_Supporting, PM2_Supporting, PM5_Supporting. LINK:https://erepo.genome.network/evrepo/ui/classification/CA273939/MONDO:0009290/010
Frequency
Consequence
NM_000152.5 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Pathogenic. Variant got 10 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152156Hom.: 0 Cov.: 33
GnomAD3 exomes AF: 0.00000829 AC: 2AN: 241258Hom.: 0 AF XY: 0.0000152 AC XY: 2AN XY: 131614
GnomAD4 exome AF: 0.00000892 AC: 13AN: 1458210Hom.: 0 Cov.: 33 AF XY: 0.0000165 AC XY: 12AN XY: 725260
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152274Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 74456
ClinVar
Submissions by phenotype
Glycogen storage disease, type II Pathogenic:8
The heterozygous p.Arg672Trp variant in GAA has been reported in the compound heterozygous state in 11 individuals (including 3 Chinese, 2 Italian, and 1 German individuals) with Glycogen Storage Disease II (PMID: 21803581, 21484825, 25526786, 21757382, 16917947, 27692865, 22676651, 9535769) and has also been reported pathogenic by EGL Genetic Diagnostics and Illumina and likely pathogenic by Counsyl in ClinVar (Variation ID: 188773). This variant has been identified in 0.003% (1/29806) of South Asian chromosomes and 0.001% (1/108738) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs757111744). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. The presence of this variant in combination with a pathogenic variant and in an individual with Glycogen Storage Disease II slightly increases the likelihood that the p.Arg672Trp variant is pathogenic (PMID: 9535769). A pathogenic variant at the the same position, p.Arg672Gln, has been associated with disease, supporting that a change at this position may not be tolerated (Variation ID: 371126). The phenotype of individuals heterozygous for this variant is highly specific for Glycogen Storage Disease II based on <10% of normal GAA activity in lymphocytes, muscle, or fibroblasts (PMID: 25526786, 9535769, 21484825, 22676651). In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic. ACMG/AMP Criteria applied: PM2, PM5, PP4, PP3, PM3_Supporting (Richards 2015). -
The GAA c.2014C>T (p.Arg672Trp) variant was identified in a compound heterozygous state in at least 11 individuals with late-onset glycogen storage disease type II (Huie et al. 1998; Sharma et al. 2005; Montalvo et al. 2006; Bali et al. 2011; Yang et al. 2011; Carlier et al. 2011; Liu et al. 2014). Control data are unavailable for this variant, but it is reported at a frequency of 0.00008 in the European (non-Finnish) population of the Exome Aggregation Consortium. GAA activity was measured at 0.1-1.0% of normal in fibroblasts from individuals carrying the p.Arg672Trp variant (Bali et al. 2011), and was decreased in muscle and lymphocytes of individuals carrying the variant (Sharma et al. 2005; Liu et al. 2014). Based on the evidence, the p.Arg672Trp variant is classified as pathogenic for glycogen storage disease type II. This variant was observed by ICSL as part of a predisposition screen in an ostensibly healthy population. -
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Variant summary: GAA c.2014C>T (p.Arg672Trp) 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 8.3e-06 in 241258 control chromosomes. c.2014C>T has been reported in the literature in individuals affected with Glycogen Storage Disease, Type 2 (Pompe Disease, e.g. Bali_2011, Angelini_2012, Liu_2014). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on GAA activity. The most pronounced variant effect was estimated to be less than 10% of normal activity (Bali_2011). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 672 of the GAA protein (p.Arg672Trp). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This missense change has been observed in individual(s) with glycogen storage disease (PMID: 9535769, 15986226). ClinVar contains an entry for this variant (Variation ID: 188773). 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%. Experimental studies have shown that this missense change affects GAA function (PMID: 9535769). This variant disrupts the p.Arg672 amino acid residue in GAA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9535769, 11053688, 19862843, 23884227, 25712382, 28592009). 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. -
The NM_000152.5:c.2014C>T variant in GAA is a missense variant predicted to cause substitution of arginine by tryptophan at amino acid 672 (p.Arg672Trp). The variant has been reported in 5 patients with a diagnosis of Pompe disease supported by <10% normal GAA activity in muscle (PMID 9535769), <1% GAA activity in cultured fibroblasts (PMID 16917947), or GAA activity in the affected range in leukocytes or lymphocytes (PMID 22676651, 25526786) in addition to at least 5 patients stated to have symptoms consistent with Pompe disease and deficient GAA activity but values not provided (PMID 16917947, 21803581, 27692865)(PP4_Moderate). At least 5 patients are compound heterozygous for the variant and a variant in GAA classified as pathogenic by the ClinGen LSD VCEP, phase unknown - c.-32-13T>G (PMID 16917947), c.2385delG (PMID 21484825), c.1411_1414del (PMID 27692865), c.766_785delinsC (PMID 9535769), and c.1951_1952insT (clinical laboratory data) (PM3_Strong). The variant has also been reported in compound heterozygotes with c.1748C>T(p.Ser583Phe)(PMID 21484825), c.323G>A (p.Cys108Tyr) (PMID 25526786), c.1465G>A (p.Asp489Asn)(PMID 16917947), c.1703A>T (p.His568Leu)(PMID 17027861, 22676651), c.2474C>G (p.Pro825Arg)(PMID 30564623). The in trans data from these patients will be used in the assessment of the second variant and is not included here in order to avoid circular logic. The highest population minor allele frequency in gnomAD v2.1.1 is 0.00003 (1/29806 alleles) in the South Asian population, which is lower than the ClinGen LSD VCEP’s threshold for PM2_Supporting (<0.001), meeting this criterion (PM2_Supporting). Expression of the variant in SV40-immortalized GAA-deficient fibroblasts revealed activity of <1% of the control value (PMID 9535769), and <2% activity in COS cells (PMID 19862843) (PS3_Supporting). The computational predictor REVEL gives a score of 0.9 which is above the threshold of 0.7, evidence that correlates with impact to GAA function (PP3). Another missense variant c.2015G>A (p.Arg672Gln)(see Table 1 in PMID 33578445) in the same codon has been classified as pathogenic for Pompe disease by the ClinGen LSD VCEP (likely pathogenic without PM5 data from c.2014C>T (p.Arg672Trp) PM5_Supporting). c.2015G>T (p.Arg672Leu) has also been reported but has not yet met the criteria to be classified as pathogenic or likely pathogenic. There is a ClinVar entry for this variant (Variation ID: 188773; 2 star status) with 5 submitters classifying the variant as pathogenic and one as likely pathogenic. In summary, this variant meets the criteria to be classified as pathogenic for Pompe disease. ACMG/AMP criteria met, as specified by the ClinGen Lysosomal Storage Disorders VCEP: PM3_Strong, PP4_Moderate, PP3, PS3_Supporting, PM2_Supporting, PM5_Supporting. -
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not provided Pathogenic:3
In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Published functional studies demonstrate a damaging effect on enzyme activity (PMID: 9535769, 19862843); Located within the Catalytic (/)8 Barrel Domain (PMID: 19343043, 22253258); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 22676651, 31980526, 30275481, 15986226, 30564623, 25526786, 21803581, 21484825, 22980766, 21757382, 16917947, 19343043, 22253258, 27692865, 9535769, 19862843, 25712382, 28937052) -
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at