chr15-72346679-C-T

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 4P and 6B. PM1PM5BP4_ModerateBS2

The NM_000520.6(HEXA):c.1178G>A(p.Arg393Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000083 in 1,614,144 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R393P) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.00012 ( 0 hom., cov: 30)

Exomes 𝑓: 0.000079 ( 2 hom. )

Consequence

HEXA
NM_000520.6 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 2.52

Publications

5 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

HEXA links:

ENSG00000261460 (HGNC:58304):

ENSG00000261460 links:

ENSG00000260729 (HGNC:):

ENSG00000260729 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 14 uncertain in NM_000520.6

PM5

Other missense variant is known to change same aminoacid residue: Variant chr15-72346679-C-G is described in ClinVar as Pathogenic. ClinVar VariationId is 218337.Status of the report is criteria_provided_single_submitter, 1 stars.

BP4

Computational evidence support a benign effect (MetaRNN=0.13550046).

BS2

High Homozygotes in GnomAdExome4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HEXA	NM_000520.6 link	c.1178G>A	p.Arg393Gln	missense_variant	Exon 11 of 14	ENST00000268097.10	NP_000511.2	P06865-1A0A0S2Z3W3
HEXA	NM_001318825.2 link	c.1211G>A	p.Arg404Gln	missense_variant	Exon 11 of 14		NP_001305754.1	P06865H3BP20B4DVA7
HEXA	NR_134869.3 link	n.1116-354G>A		intron_variant	Intron 9 of 10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HEXA	ENST00000268097.10 link	c.1178G>A	p.Arg393Gln	missense_variant	Exon 11 of 14	1	NM_000520.6	ENSP00000268097.6		P06865-1
ENSG00000260729	ENST00000379915.4 link	n.413-354G>A		intron_variant	Intron 3 of 15	2		ENSP00000478716.1		A0A087WUJ7

Frequencies

GnomAD3 genomes

AF:

0.000125

AC:

AN:

152196

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000314

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.000414

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000588

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.000103

AC:

AN:

251478

AF XY:

0.000147

show subpopulations

Gnomad AFR exome

AF:

0.000123

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:

0.0000176

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000787

AC:

115

AN:

1461830

Hom.:

Cov.:

AF XY:

0.000109

AC XY:

AN XY:

727212

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.000835

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5734

European-Non Finnish (NFE)

AF:

0.0000351

AC:

AN:

1112004

Other (OTH)

AF:

0.0000662

AC:

AN:

60386

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.476

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<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:

0.000125

AC:

AN:

152314

Hom.:

Cov.:

AF XY:

0.000107

AC XY:

AN XY:

74480

show subpopulations

African (AFR)

AF:

0.000313

AC:

AN:

41578

American (AMR)

AF:

0.00

AC:

AN:

15294

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.000414

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.0000588

AC:

AN:

68032

Other (OTH)

AF:

0.00

AC:

AN:

2110

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.512

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<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:

0.0000766

Hom.:

Bravo

AF:

0.000125

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.000107

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Tay-Sachs disease

Uncertain:3

Sep 16, 2020

Natera, Inc.

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Nov 16, 2017

Counsyl

Significance:Uncertain significance

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. -

Sep 01, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 393 of the HEXA protein (p.Arg393Gln). This variant is present in population databases (rs370266293, gnomAD 0.07%). This variant has not been reported in the literature in individuals affected with HEXA-related conditions. ClinVar contains an entry for this variant (Variation ID: 554870). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not specified

Uncertain:1

Aug 09, 2018

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The HEXA c.1178G>A; p.Arg393Gln variant (rs370266293), to our knowledge, is not reported in the medical literature or gene specific databases; however, another variant at this codon (c.1178G>C; p.R393P) has been reported in the homozygous state in an individual with Tay-Sachs disease (Mistri 2012). This variant is found in the South Asian population with an overall allele frequency of 0.07% (21/30780 alleles) in the Genome Aggregation Database. The arginine at codon 393 is moderately conserved, and computational analyses (SIFT: damaging, PolyPhen-2: benign) predict conflicting effects of the p.Arg393Gln variant on protein structure/function. Due to limited information, the clinical significance of the p.Arg393Gln variant is uncertain at this time. -

Inborn genetic diseases

Uncertain:1

May 07, 2025

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.1178G>A (p.R393Q) alteration is located in exon 11 (coding exon 11) of the HEXA gene. This alteration results from a G to A substitution at nucleotide position 1178, causing the arginine (R) at amino acid position 393 to be replaced by a glutamine (Q). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.099

BayesDel_addAF

Benign

-0.11

BayesDel_noAF

Uncertain

-0.030

CADD

Uncertain

(source)

DANN

Pathogenic

1.0

DEOGEN2

Uncertain

0.76

D;.;D

Eigen

Benign

0.015

Eigen_PC

Benign

0.041

FATHMM_MKL

Benign

0.71

LIST_S2

Benign

0.79

T;T;T

M_CAP

Uncertain

0.17

MetaRNN

Benign

0.14

T;T;T

MetaSVM

Uncertain

0.33

MutationAssessor

Benign

1.8

L;.;.

PhyloP100

2.5

PrimateAI

Benign

0.31

PROVEAN

Benign

-0.99

N;N;N

REVEL

Uncertain

0.41

Sift

Uncertain

0.016

D;D;D

Sift4G

Uncertain

0.048

D;D;D

Polyphen

0.85

P;.;.

Vest4

0.20

MVP

0.95

MPC

0.26

ClinPred

0.089

GERP RS

3.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.30

gMVP

0.73

Mutation Taster

=76/24

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over