rs750727201

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_000520.6(HEXA):​c.1393G>A​(p.Asp465Asn) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000471 in 1,613,822 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).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000051 ( 0 hom. )

Consequence

HEXA
NM_000520.6 missense

Scores

10
6
3

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:6U:1

Conservation

PhyloP100: 7.81
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP3
MetaRNN computational evidence supports a deleterious effect, 0.987
PP5
Variant 15-72346263-C-T is Pathogenic according to our data. Variant chr15-72346263-C-T is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 555154.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=4, Uncertain_significance=1}.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
HEXANM_000520.6 linkc.1393G>A p.Asp465Asn missense_variant Exon 12 of 14 ENST00000268097.10 NP_000511.2 P06865-1A0A0S2Z3W3
HEXANM_001318825.2 linkc.1426G>A p.Asp476Asn missense_variant Exon 12 of 14 NP_001305754.1 P06865H3BP20B4DVA7
HEXANR_134869.3 linkn.1178G>A 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.1393G>A p.Asp465Asn missense_variant Exon 12 of 14 1 NM_000520.6 ENSP00000268097.6 P06865-1
ENSG00000260729ENST00000379915.4 linkn.475G>A non_coding_transcript_exon_variant Exon 4 of 16 2 ENSP00000478716.1 A0A087WUJ7

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152118
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.0000119
AC:
3
AN:
251186
Hom.:
0
AF XY:
0.00000737
AC XY:
1
AN XY:
135760
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 SAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000513
AC:
75
AN:
1461704
Hom.:
0
Cov.:
31
AF XY:
0.0000426
AC XY:
31
AN XY:
727138
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.0000224
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
0.0000666
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152118
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74300
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00
Alfa
AF:
0.0000278
Hom.:
0
Bravo
AF:
0.00000756
TwinsUK
AF:
0.000270
AC:
1
ALSPAC
AF:
0.00
AC:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:6Uncertain:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Tay-Sachs disease Pathogenic:3Uncertain:1
Oct 10, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces aspartic acid, which is acidic and polar, with asparagine, which is neutral and polar, at codon 465 of the HEXA protein (p.Asp465Asn). This variant is present in population databases (rs750727201, gnomAD 0.003%). This missense change has been observed in individual(s) with Tay Sachs disease (PMID: 11317368; internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 555154). 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) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on HEXA protein function. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Nov 19, 2017
Counsyl
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

May 15, 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.1393G>A (p.Asp465Asn) results in a conservative amino acid change located in the Glycoside hydrolase family 20, catalytic domain (IPR015883) of the encoded protein sequence. Three of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.2e-05 in 251186 control chromosomes (gnomAD). c.1393G>A has been reported in the literature in a homozygous individual affected with Tay-Sachs Disease (TSD) whose parents and extended family were enzymatically defined as TSD carriers (example: Alvarez-Rodriguez_2001). This individual also had two affected brothers however, authors did not specify if the affected siblings DNA analysis was performed. These data indicate that the variant may be associated with disease. 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: 11317368, 24583203). Five clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as likely pathogenic (n=4) and VUS (n=1). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Dec 06, 2017
Natera, Inc.
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

- -

HEXA-related disorder Pathogenic:1
Nov 21, 2023
PreventionGenetics, part of Exact Sciences
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: clinical testing

The HEXA c.1393G>A variant is predicted to result in the amino acid substitution p.Asp465Asn. This variant was reported in homozygous state in an individual with Tay-Sachs disease (TSD) and parents together with four other family members, who were heterozygotes for this variant, were enzymatically defined as TSD carriers (Alvarez-Rodriguez et al. 2001. PubMed ID: 11317368). This variant is reported in 0.0029% of alleles in individuals of Latino descent in gnomAD. This variant is interpreted as likely pathogenic. -

Inborn genetic diseases Pathogenic:1
Feb 17, 2022
Ambry Genetics
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The c.1393G>A (p.D465N) alteration is located in exon 12 (coding exon 12) of the HEXA gene. This alteration results from a G to A substitution at nucleotide position 1393, causing the aspartic acid (D) at amino acid position 465 to be replaced by an asparagine (N). Based on data from gnomAD, the A allele has an overall frequency of 0.001% (3/251186) total alleles studied. The highest observed frequency was 0.003% (1/34554) of Latino alleles. This alteration has been reported homozygous in a patient with Tay Sachs disease. The 5 year old boy had exaggerated startle response, myoclonic jerks, progressive weakness, diminished muscle tone, and decreased eye contact. He eventually had loss of previously acquired skills, tonic seizures, hyperreflexia, increasing muscle stiffness and progressive spasticity, as well as a cherry red spot in the macula. There was no hepatomegaly or splenomegaly. His parents were enzymatically confirmed as Tay Sachs carriers and were found to be heterozygous for the c.1393G>A alteration (Alvarez-Rodríguez, 2001). This amino acid position is highly conserved in available vertebrate species. This alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, this alteration is classified as likely pathogenic. -

not provided Pathogenic:1
Dec 04, 2018
GeneDx
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Not observed at a significant frequency in large population cohorts (Lek et al., 2016); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 11317368, 24498621, 24583203) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.81
BayesDel_addAF
Uncertain
0.077
D
BayesDel_noAF
Uncertain
-0.040
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.97
D;.;D
Eigen
Pathogenic
0.85
Eigen_PC
Pathogenic
0.84
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D;D;D
M_CAP
Uncertain
0.27
D
MetaRNN
Pathogenic
0.99
D;D;D
MetaSVM
Pathogenic
1.0
D
MutationAssessor
Uncertain
2.3
M;.;.
PrimateAI
Uncertain
0.75
T
PROVEAN
Pathogenic
-4.7
D;D;D
REVEL
Pathogenic
0.73
Sift
Benign
0.13
T;T;T
Sift4G
Benign
0.15
T;T;T
Polyphen
0.96
D;.;.
Vest4
0.92
MutPred
0.94
Gain of MoRF binding (P = 0.0754);.;Gain of MoRF binding (P = 0.0754);
MVP
0.99
MPC
0.74
ClinPred
0.97
D
GERP RS
5.8
RBP_binding_hub_radar
0.97
RBP_regulation_power_radar
2.7
Varity_R
0.78
gMVP
0.91

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs750727201; hg19: chr15-72638604; API