NM_000520.6:c.533G>T

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PM2PM5PP3_StrongPP5_Moderate

The NM_000520.6(HEXA):​c.533G>T​(p.Arg178Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,613,180 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 Likely pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R178C) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

HEXA
NM_000520.6 missense

Scores

15
3
1

Clinical Significance

Likely pathogenic criteria provided, single submitter P:1O:1

Conservation

PhyloP100: 7.81

Publications

40 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 12 ACMG points.

PM1
In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 7 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 chr15-72353106-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 3897.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.992
PP5
Variant 15-72353105-C-A is Pathogenic according to our data. Variant chr15-72353105-C-A is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 3912.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.533G>T p.Arg178Leu missense_variant Exon 5 of 14 ENST00000268097.10 NP_000511.2 P06865-1A0A0S2Z3W3
HEXANM_001318825.2 linkc.566G>T p.Arg189Leu missense_variant Exon 5 of 14 NP_001305754.1 P06865H3BP20B4DVA7
HEXANR_134869.3 linkn.575G>T non_coding_transcript_exon_variant Exon 5 of 11

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HEXAENST00000268097.10 linkc.533G>T p.Arg178Leu missense_variant Exon 5 of 14 1 NM_000520.6 ENSP00000268097.6 P06865-1
ENSG00000260729ENST00000379915.4 linkn.412+2454G>T intron_variant Intron 3 of 15 2 ENSP00000478716.1 A0A087WUJ7

Frequencies

GnomAD3 genomes
AF:
0.00000658
AC:
1
AN:
152090
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000655
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461090
Hom.:
0
Cov.:
30
AF XY:
0.00
AC XY:
0
AN XY:
726890
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33456
American (AMR)
AF:
0.00
AC:
0
AN:
44710
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86240
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5762
European-Non Finnish (NFE)
AF:
9.00e-7
AC:
1
AN:
1111342
Other (OTH)
AF:
0.00
AC:
0
AN:
60344
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
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
AF:
0.00000658
AC:
1
AN:
152090
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74294
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41394
American (AMR)
AF:
0.0000655
AC:
1
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5194
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4828
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10608
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68008
Other (OTH)
AF:
0.00
AC:
0
AN:
2088
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0

ClinVar

Significance: Likely pathogenic
Submissions summary: Pathogenic:1Other:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

not provided Pathogenic:1
Jul 06, 2023
Quest Diagnostics Nichols Institute San Juan Capistrano
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

In the published literature, this variant has been reported in an individual with Tay-Sachs disease (PMID: 1833974 (1991)). A structural analysis study predicts this variant causes a significant change in the active site pocket structure (PMID: 18490185 (2008)). The frequency of this variant in the general population, 0.0000066 (1/152090 chromosomes (Genome Aggregation Database, http://gnomad.broadinstitute.org)), is uninformative in the assessment of its pathogenicity. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is damaging. Based on the available information, this variant is classified as likely pathogenic. -

Tay-Sachs disease Other:1
Nov 01, 1991
OMIM
Significance:Affects
Review Status:no assertion criteria provided
Collection Method:literature only

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.98
BayesDel_addAF
Pathogenic
0.58
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.99
D;.;D
Eigen
Pathogenic
1.1
Eigen_PC
Pathogenic
1.0
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.99
D;D;D
M_CAP
Pathogenic
0.41
D
MetaRNN
Pathogenic
0.99
D;D;D
MetaSVM
Pathogenic
0.94
D
MutationAssessor
Pathogenic
4.2
H;.;.
PhyloP100
7.8
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-6.7
D;D;D
REVEL
Pathogenic
0.99
Sift
Pathogenic
0.0
D;D;D
Sift4G
Uncertain
0.0020
D;D;D
Polyphen
1.0
D;.;.
Vest4
0.97
MutPred
0.99
Loss of disorder (P = 0.0893);.;Loss of disorder (P = 0.0893);
MVP
1.0
MPC
0.84
ClinPred
1.0
D
GERP RS
5.4
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.98
gMVP
0.98
Mutation Taster
=197/103
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.060
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: rs28941770; hg19: chr15-72645446; API