15-72346235-C-T

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1PM2PP3_StrongPP5_Moderate

The NM_000520.6(HEXA):​c.1421G>A​(p.Trp474*) variant causes a stop gained, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000685 in 1,460,592 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

HEXA
NM_000520.6 stop_gained, splice_region

Scores

4
2
1
Splicing: ADA: 0.9999
2

Clinical Significance

Pathogenic criteria provided, single submitter P:3

Conservation

PhyloP100: 7.81

Publications

1 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 16 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;
PP3
Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.
PP5
Variant 15-72346235-C-T is Pathogenic according to our data. Variant chr15-72346235-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 371169.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HEXANM_000520.6 linkc.1421G>A p.Trp474* stop_gained, splice_region_variant Exon 12 of 14 ENST00000268097.10 NP_000511.2
HEXANM_001318825.2 linkc.1454G>A p.Trp485* stop_gained, splice_region_variant Exon 12 of 14 NP_001305754.1
HEXANR_134869.3 linkn.1206G>A splice_region_variant, non_coding_transcript_exon_variant Exon 10 of 11

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HEXAENST00000268097.10 linkc.1421G>A p.Trp474* stop_gained, splice_region_variant Exon 12 of 14 1 NM_000520.6 ENSP00000268097.6
ENSG00000260729ENST00000379915.4 linkn.503G>A splice_region_variant, non_coding_transcript_exon_variant Exon 4 of 16 2 ENSP00000478716.1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.85e-7
AC:
1
AN:
1460592
Hom.:
0
Cov.:
30
AF XY:
0.00000138
AC XY:
1
AN XY:
726646
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33456
American (AMR)
AF:
0.00
AC:
0
AN:
44640
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26100
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39690
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86162
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5754
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111048
Other (OTH)
AF:
0.00
AC:
0
AN:
60334
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.625
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

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
Cov.:
32
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Tay-Sachs disease Pathogenic:3
Jun 13, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This premature translational stop signal has been observed in individual(s) with lysosomal storage disorders (PMID: 23852624). ClinVar contains an entry for this variant (Variation ID: 371169). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. This variant is not present in population databases (gnomAD no frequency). This sequence change creates a premature translational stop signal (p.Trp474*) 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). -

Jul 19, 2016
Counsyl
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

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. -

Jul 07, 2012
Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics
Significance:Pathogenic
Review Status:no assertion criteria provided
Collection Method:research

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_addAF
Pathogenic
0.63
D
BayesDel_noAF
Pathogenic
0.65
CADD
Pathogenic
55
DANN
Uncertain
0.99
Eigen
Pathogenic
0.68
Eigen_PC
Uncertain
0.56
FATHMM_MKL
Pathogenic
0.99
D
PhyloP100
7.8
Vest4
0.95
GERP RS
4.9
RBP_binding_hub_radar
0.92
RBP_regulation_power_radar
2.6
Mutation Taster
=0/200
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
1.0
SpliceAI score (max)
0.29
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.29
Position offset: 49

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

Publications

Other links and lift over

dbSNP: rs762374961; hg19: chr15-72638576; API