chr15-72349163-A-C

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PP3_StrongPP5

The NM_000520.6(HEXA):​c.902T>G​(p.Met301Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000118 in 1,613,758 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M301L) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

HEXA
NM_000520.6 missense

Scores

12
6
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:1O:1

Conservation

PhyloP100: 9.21

Publications

6 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: Uncertain_significance. The variant received 5 ACMG points.

PP3
MetaRNN computational evidence supports a deleterious effect, 0.983
PP5
Variant 15-72349163-A-C is Pathogenic according to our data. Variant chr15-72349163-A-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 3933.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HEXANM_000520.6 linkc.902T>G p.Met301Arg missense_variant Exon 8 of 14 ENST00000268097.10 NP_000511.2 P06865-1A0A0S2Z3W3
HEXANM_001318825.2 linkc.935T>G p.Met312Arg missense_variant Exon 8 of 14 NP_001305754.1 P06865H3BP20B4DVA7
HEXANR_134869.3 linkn.944T>G non_coding_transcript_exon_variant Exon 8 of 11

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
HEXAENST00000268097.10 linkc.902T>G p.Met301Arg missense_variant Exon 8 of 14 1 NM_000520.6 ENSP00000268097.6 P06865-1
ENSG00000260729ENST00000379915.4 linkn.413-2838T>G intron_variant Intron 3 of 15 2 ENSP00000478716.1 A0A087WUJ7

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152258
Hom.:
0
Cov.:
32
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:
0.000207
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000159
AC:
4
AN:
251438
AF XY:
0.0000294
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000123
AC:
18
AN:
1461500
Hom.:
0
Cov.:
31
AF XY:
0.0000179
AC XY:
13
AN XY:
727104
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.000186
AC:
16
AN:
86252
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
9.00e-7
AC:
1
AN:
1111650
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60388
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.478
Heterozygous variant carriers
0
2
4
6
8
10
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:
0.00000657
AC:
1
AN:
152258
Hom.:
0
Cov.:
32
AF XY:
0.0000134
AC XY:
1
AN XY:
74402
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41458
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.000207
AC:
1
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68054
Other (OTH)
AF:
0.00
AC:
0
AN:
2092
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

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:
0.00
Hom.:
0
ExAC
AF:
0.0000247
AC:
3

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:1Other:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Tay-Sachs disease Pathogenic:3Uncertain:1Other:1
Mar 30, 2022
MGZ Medical Genetics Center
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jan 01, 1993
OMIM
Significance:Affects
Review Status:no assertion criteria provided
Collection Method:literature only

- -

May 03, 2023
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: HEXA c.902T>G (p.Met301Arg) results in a non-conservative amino acid change located in the Glycoside hydrolase family 20, catalytic domain (IPR015883) of 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 1.6e-05 in 251438 control chromosomes. c.902T>G has been reported in the literature in homozygous and compound heterozygous individuals affected with Tay-Sachs Disease (Akil_1993, Cheema_2020). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 8490625, 33083013). Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified as Pathogenic (n=1), Likely Pathogenic (n=1) and VUS (n=1). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Aug 28, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

ClinVar contains an entry for this variant (Variation ID: 3933). This missense change has been observed in individual(s) with Tay-Sachs disease (PMID: 8490625, 33083013). This variant is present in population databases (rs121907977, gnomAD 0.01%). This sequence change replaces methionine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 301 of the HEXA protein (p.Met301Arg). 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 HEXA protein function. For these reasons, this variant has been classified as Pathogenic. -

Feb 21, 2020
Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

A heterozygous missense variation in exon 8 of the HEXA gene that results in the amino acid substitution of Arginine for Methionine at codon 301 was detected. The observed variant c.902T>G (p.Met301Arg) has not been reported in the 1000 genomes and ExAC databases. The in silico prediction of the variant is possibly damaging by PolyPhen-2 (HumDiv) and damaging by MutationTaster2. The reference codon is conserved across species. In summary, the variant meets our criteria to be classified as likely pathogenic. -

Tay-Sachs disease;C0268275:Tay-Sachs disease, variant AB Pathogenic:1
-
CENTOGENE GmbH and LLC - Guiding Precision Medicine
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.88
BayesDel_addAF
Pathogenic
0.38
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
26
DANN
Uncertain
0.98
DEOGEN2
Pathogenic
0.97
D;.;D
Eigen
Pathogenic
0.76
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.92
D;D;D
M_CAP
Uncertain
0.21
D
MetaRNN
Pathogenic
0.98
D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
3.0
M;.;.
PhyloP100
9.2
PrimateAI
Uncertain
0.61
T
PROVEAN
Pathogenic
-4.9
D;D;D
REVEL
Pathogenic
0.96
Sift
Uncertain
0.0010
D;D;D
Sift4G
Uncertain
0.0020
D;D;D
Polyphen
0.97
D;.;.
Vest4
0.97
MutPred
0.91
Gain of catalytic residue at M301 (P = 0.0631);.;Gain of catalytic residue at M301 (P = 0.0631);
MVP
0.99
MPC
0.93
ClinPred
0.97
D
GERP RS
5.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.99
gMVP
0.99
Mutation Taster
=4/96
disease causing (ClinVar)

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.0
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: rs121907977; hg19: chr15-72641504; API