rs121907962

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000520.6(HEXA):​c.409C>T​(p.Arg137*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000587 in 1,601,902 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 Pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. R137R) has been classified as Uncertain significance. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000061 ( 0 hom. )

Consequence

HEXA
NM_000520.6 stop_gained

Scores

2
4
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7O:1

Conservation

PhyloP100: 1.16

Publications

8 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.

PVS1
Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 15-72355562-G-A is Pathogenic according to our data. Variant chr15-72355562-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 3904.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.409C>T p.Arg137* stop_gained Exon 3 of 14 ENST00000268097.10 NP_000511.2 P06865-1A0A0S2Z3W3
HEXANM_001318825.2 linkc.442C>T p.Arg148* stop_gained Exon 3 of 14 NP_001305754.1 P06865H3BP20B4DVA7
HEXANR_134869.3 linkn.451C>T non_coding_transcript_exon_variant Exon 3 of 11

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HEXAENST00000268097.10 linkc.409C>T p.Arg137* stop_gained Exon 3 of 14 1 NM_000520.6 ENSP00000268097.6 P06865-1
ENSG00000260729ENST00000379915.4 linkn.409C>T non_coding_transcript_exon_variant Exon 3 of 16 2 ENSP00000478716.1 A0A087WUJ7

Frequencies

GnomAD3 genomes
AF:
0.0000329
AC:
5
AN:
151954
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000242
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:
0.0000588
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000239
AC:
6
AN:
251404
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:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000440
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000614
AC:
89
AN:
1449948
Hom.:
0
Cov.:
27
AF XY:
0.0000678
AC XY:
49
AN XY:
722320
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33272
American (AMR)
AF:
0.00
AC:
0
AN:
44708
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26054
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39618
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86028
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53402
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5746
European-Non Finnish (NFE)
AF:
0.0000772
AC:
85
AN:
1101168
Other (OTH)
AF:
0.0000500
AC:
3
AN:
59952
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.467
Heterozygous variant carriers
0
4
7
11
14
18
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
10
20
30
40
50
<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:
0.0000329
AC:
5
AN:
151954
Hom.:
0
Cov.:
32
AF XY:
0.0000539
AC XY:
4
AN XY:
74214
show subpopulations
African (AFR)
AF:
0.0000242
AC:
1
AN:
41348
American (AMR)
AF:
0.00
AC:
0
AN:
15244
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5186
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4810
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10582
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000588
AC:
4
AN:
67994
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.505
Heterozygous variant carriers
0
1
2
2
3
4
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:
0.0000928
Hom.:
0
Bravo
AF:
0.0000340
ExAC
AF:
0.0000165
AC:
2
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:7Other:1
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Tay-Sachs disease Pathogenic:5Other:1
Mar 17, 2017
Natera, Inc.
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Jan 05, 2022
DASA
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.409C>T;p.(Arg137*) variant creates a premature translational stop signal in the the HEXA gene. It is expected to result in an absent or disrupted protein product -PVS1. This sequence change has been observed in affected individual(s) and ClinVar contains an entry for this variant (Clinvar ID: 3904; PMID: 1532289; 1837283; 9851891; 14685153; 18648917; 22441121; 22789865) - PS4. The variant is present at low allele frequencies population databases (rs121907962– gnomAD 0,00329%; ABraOM 0.000854 frequency - http://abraom.ib.usp.br/) - PM2_supporting. The p.(Arg137*) was detected in trans with a pathogenic variant (PMID: 1837283; 1864891; 9851891; 22441121; 22789865) - PM3_strong. In summary, the currently available evidence indicates that the variant is pathogenic. -

Apr 01, 1992
OMIM
Significance:Affects
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Feb 16, 2022
Fulgent Genetics, Fulgent Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Nov 03, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg137*) in the HEXA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HEXA are known to be pathogenic (PMID: 1833974, 8490625). This variant is present in population databases (rs121907962, gnomAD 0.006%). This premature translational stop signal has been observed in individual(s) with hexosaminidase A deficiency (PMID: 1837283, 18648917, 22441121, 22789865). ClinVar contains an entry for this variant (Variation ID: 3904). For these reasons, this variant has been classified as Pathogenic. -

Jul 23, 2018
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: HEXA c.409C>T (p.Arg137X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. The variant allele was found at a frequency of 2.9e-05 in 277008 control chromosomes. c.409C>T has been reported in the literature in individuals affected with Tay-Sachs Disease (Gort_2012, Mules_1992, Ozkara_1998, Zampieri_2012). These data indicate that the variant is associated with disease. Two 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. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:2
Apr 27, 2016
GeneDx
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The R137X pathogenic variant in the HEXA gene has been reported previously in association with Tay Sachs disease (Akli et al., 1991; Mules et al., 1992). This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The R137X variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. We interpret R137X as a pathogenic variant. -

Nov 06, 2015
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.53
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
39
DANN
Uncertain
1.0
Eigen
Uncertain
0.59
Eigen_PC
Uncertain
0.43
FATHMM_MKL
Uncertain
0.89
D
PhyloP100
1.2
Vest4
0.98
GERP RS
3.0
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
Splicevardb
2.0
SpliceAI score (max)
0.12
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: rs121907962; hg19: chr15-72647903; COSMIC: COSV51505186; COSMIC: COSV51505186; API