rs28942071

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000520.6(HEXA):​c.1510C>T​(p.Arg504Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000192 in 1,614,060 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R504L) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 34)
Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

HEXA
NM_000520.6 missense

Scores

15
2
2

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:12

Conservation

PhyloP100: 9.43

Publications

16 publications found
Variant links:
Genes affected
HEXA (HGNC:4878): (hexosaminidase subunit alpha) This gene encodes a member of the glycosyl hydrolase 20 family of proteins. The encoded preproprotein is proteolytically processed to generate the alpha subunit of the lysosomal enzyme beta-hexosaminidase. This enzyme, together with the cofactor GM2 activator protein, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. Mutations in this gene lead to an accumulation of GM2 ganglioside in neurons, the underlying cause of neurodegenerative disorders termed the GM2 gangliosidoses, including Tay-Sachs disease (GM2-gangliosidosis type I). Alternative splicing results in multiple transcript variants, at least one of which encodes a preproprotein that is proteolytically processed. [provided by RefSeq, Jan 2016]
HEXA Gene-Disease associations (from GenCC):
  • Tay-Sachs disease
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Myriad Women’s Health, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), ClinGen

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 6 uncertain in NM_000520.6
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr15-72345461-C-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 555956.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.97
PP5
Variant 15-72345462-G-A is Pathogenic according to our data. Variant chr15-72345462-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 3906.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HEXANM_000520.6 linkc.1510C>T p.Arg504Cys missense_variant Exon 13 of 14 ENST00000268097.10 NP_000511.2 P06865-1A0A0S2Z3W3
HEXANM_001318825.2 linkc.1543C>T p.Arg515Cys missense_variant Exon 13 of 14 NP_001305754.1 P06865H3BP20B4DVA7
HEXANR_134869.3 linkn.1295C>T non_coding_transcript_exon_variant Exon 11 of 11

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HEXAENST00000268097.10 linkc.1510C>T p.Arg504Cys missense_variant Exon 13 of 14 1 NM_000520.6 ENSP00000268097.6 P06865-1
ENSG00000260729ENST00000379915.4 linkn.592C>T non_coding_transcript_exon_variant Exon 5 of 16 2 ENSP00000478716.1 A0A087WUJ7

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152228
Hom.:
0
Cov.:
34
show subpopulations
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:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251454
AF XY:
0.0000147
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000352
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000198
AC:
29
AN:
1461832
Hom.:
0
Cov.:
35
AF XY:
0.0000193
AC XY:
14
AN XY:
727220
show subpopulations
African (AFR)
AF:
0.0000896
AC:
3
AN:
33480
American (AMR)
AF:
0.0000224
AC:
1
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000216
AC:
24
AN:
1111968
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
Heterozygous variant carriers
0
2
4
5
7
9
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.0000131
AC:
2
AN:
152228
Hom.:
0
Cov.:
34
AF XY:
0.0000134
AC XY:
1
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41454
American (AMR)
AF:
0.00
AC:
0
AN:
15286
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10628
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68034
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.0000431
Hom.:
0
Bravo
AF:
0.0000189
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:12
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Tay-Sachs disease Pathogenic:9
Apr 03, 2019
Centre for Mendelian Genomics, University Medical Centre Ljubljana
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was classified as: Likely pathogenic. The following ACMG criteria were applied in classifying this variant: PM2,PS1,PP3. -

Sep 18, 2017
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: The HEXA c.1510C>T (p.Arg504Cys) variant causes a missense change involving the alteration of a conserved nucleotide located in the Glycoside hydrolase superfamily domain (IPR017853) (InterPro). 5/5 in silico tools predict a damaging outcome for this variant. One functional study confirmed these predictions by finding no enzymatic activity associated with this variant (Paw_1991). The variant was found in the control population dataset of ExAC in 2/121476 control chromosomes at a frequency of 0.0000165, which does not exceed the estimated maximal expected allele frequency of a pathogenic HEXA variant (0.0013975). This variant was reported in multiple patients with Tay-Sachs disease, as a homozygous allele (Akli_1991) and in compound heterozygosity with c.805G>A (p.G269S)(pathogenic in our internal database), c.615delG (p.V206X)(not in our internal database, not in HGMD/ClinVar), and c.346+1G>A (not in our internal database, DM in HGMD)(Neudorfer_2005, Montalvo_2005, Akli_1991). In addition, multiple clinical diagnostic laboratories/reputable databases classified this variant as likely pathogenic/pathogenic. Taken together, this variant is classified as pathogenic. -

Apr 18, 2014
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Mar 17, 2017
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

May 28, 2019
Mendelics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Dec 22, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 504 of the HEXA protein (p.Arg504Cys). This variant is present in population databases (rs28942071, gnomAD 0.006%). This missense change has been observed in individual(s) with Tay–Sachs disease (PMID: 1837283, 19091716, 25860343). ClinVar contains an entry for this variant (Variation ID: 3906). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt HEXA protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects HEXA function (PMID: 9694901). For these reasons, this variant has been classified as Pathogenic. -

Feb 18, 2024
3billion
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.002%). Predicted Consequence/Location: Missense variant In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.94 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.94 (>=0.6, sensitivity 0.72 and precision 0.9)]. Same nucleotide change resulting in same amino acid change has been previously reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000003906 /PMID: 1837283 /3billion dataset). The variant has been reported to be in trans with a pathogenic variant as either compound heterozygous or homozygous in at least one similarly affected unrelated individual (PMID: 15714079, 16088929, 1837283). Different missense changes at the same codon (p.Arg504His, p.Arg504Leu) have been reported as pathogenic/likely pathogenic with strong evidence (ClinVar ID: VCV000003895 /PMID: 2140574, 22441121). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Aug 05, 2022
Institute of Human Genetics Munich, TUM University Hospital
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jul 17, 2023
Victorian Clinical Genetics Services, Murdoch Childrens Research Institute
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is a known mechanism of disease in this gene and is associated with Tay-Sachs disease (MIM#272800). (I) 0106 - This gene is associated with autosomal recessive disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to cysteine. (I) 0251 - This variant is heterozygous. (I) 0304 - Variant is present in gnomAD (v2) <0.01 for a recessive condition (6 heterozygotes, 0 homozygotes). (SP) 0309 - Multiple alternative amino acid changes at the same position has been observed in gnomAD (v2 and 3) (highest allele count: 3 heterozygotes, 0 homozygotes). (I) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. This variant has been classified as pathogenic or likely pathogenic by multiple clinical laboratories in ClinVar, and has been observed in individuals with Tay-Sachs disease (PMIDs: 16088929, 15714079). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

not specified Pathogenic:1
Dec 17, 2018
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The HEXA c.1510C>T; p.Arg504Cys variant (rs28942071) has been described in individuals affected with Tay-Sachs disease (TSD; Alki 1991, Montalvo 2005, Neudorfer 2005, Shapiro 2009) and GM2-gangliosidosis (Ragahavan 1985). It contains an entry in ClinVar (Variation ID: 3906) and is observed in the general population at a low overall frequency of 0.0024% (6/251454 alleles) in the Genome Aggregation database. Fibroblasts from patients harboring this variant show reduced beta-hexosaminidase A and defective GM2 ganglioside metabolism (Raghavan 1985). Further analyses of the variant protein demonstrate impaired dimerization and loss of association of alpha and beta subunits (d'Azzo 1984, Paw 1991). Additionally, other variants at this codon (c.1511G>A; p.Arg504His and c.1511G>T; p.Arg504Leu) have been described in individuals affected with TSD (Montalvo 2005, Zampieri 2012). Based on available information, the p.Arg504Cys variant is considered pathogenic. REFERENCES Alki S et al. Seven novel Tay-Sachs mutations detected by chemical mismatch cleavage of PCR-amplified cDNA fragments. Genomics. 1991 Sep;11(1):124-34. d'Azzo A et al. Faulty association of alpha- and beta-subunits in some forms of beta-hexosaminidase A deficiency. J Biol Chem. 1984 Sep 10;259(17):11070-4. Montalvo A et al. Molecular analysis of the HEXA gene in Italian patients with infantile and late onset Tay-Sachs disease: detection of fourteen novel alleles. Hum Mutat. 2005 Sep;26(3):282. Neudorfer O et al. Late-onset Tay-Sachs disease: phenotypic characterization and genotypic correlations in 21 affected patients. Genet Med. 2005 Feb;7(2):119-23. Paw B et al. A third mutation at the CpG dinucleotide of codon 504 and a silent mutation at codon 506 of the HEX A gene. Am J Hum Genet. 1991 Jun;48(6):1139-46. Raghavan S et al. GM2-ganglioside metabolism in hexosaminidase A deficiency states: determination in situ using labeled GM2 added to fibroblast cultures. Am J Hum Genet. 1985 Nov;37(6):1071-82. Shapiro B et al. Late-onset Tay-Sachs disease presenting as a childhood stutter. J Neurol Neurosurg Psychiatry. 2009 Jan;80(1):94-5. Zampieri S et al. Molecular analysis of HEXA gene in Argentinean patients affected with Tay-Sachs disease: possible common origin of the prevalent c.459+5A>G mutation. Gene. 2012 May 15;499(2):262-5. -

not provided Pathogenic:1
Apr 03, 2019
Mayo Clinic Laboratories, Mayo Clinic
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PS3, PS4_moderate, PM2, PM3, PM5, PP1, PP4 -

Gm2-gangliosidosis, chronic Pathogenic:1
Sep 01, 1991
OMIM
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.88
BayesDel_addAF
Pathogenic
0.46
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.91
D;.;T
Eigen
Pathogenic
0.96
Eigen_PC
Pathogenic
0.87
FATHMM_MKL
Pathogenic
1.0
D
LIST_S2
Pathogenic
0.98
D;D;D
M_CAP
Pathogenic
0.37
D
MetaRNN
Pathogenic
0.97
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.6
H;.;.
PhyloP100
9.4
PrimateAI
Benign
0.47
T
PROVEAN
Pathogenic
-7.4
D;D;D
REVEL
Pathogenic
0.94
Sift
Uncertain
0.0030
D;D;D
Sift4G
Uncertain
0.0040
D;D;D
Polyphen
1.0
D;.;.
Vest4
0.97
MVP
1.0
MPC
0.88
ClinPred
1.0
D
GERP RS
5.7
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.85
gMVP
0.95
Mutation Taster
=1/99
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.070
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs28942071; hg19: chr15-72637803; COSMIC: COSV51507186; COSMIC: COSV51507186; API