15-72351132-C-T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 14 ACMG points: 14P and 0B. PM2PP3_StrongPP5_Very_Strong

The ENST00000570175.1(ENSG00000261460):n.2486C>T variant causes a non coding transcript exon change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000488 in 1,433,838 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 Pathogenic (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000049 ( 0 hom. )

Consequence

ENSG00000261460
ENST00000570175.1 non_coding_transcript_exon

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 7.81

Publications

3 publications found

Variant links:

Genes affected

ENSG00000261460 (HGNC:58304):

ENSG00000261460 links:

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:

ENSG00000260729 (HGNC:):

ENSG00000260729 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 14 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing predictors support a deleterious effect. Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 15-72351132-C-T is Pathogenic according to our data. Variant chr15-72351132-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 3928.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	Exon rank	MANE	Protein	UniProt
HEXA	NM_000520.6 link	c.672+1G>A	splice_donor_variant, intron_variant	Intron 6 of 13	ENST00000268097.10	NP_000511.2	P06865-1A0A0S2Z3W3
HEXA	NM_001318825.2 link	c.705+1G>A	splice_donor_variant, intron_variant	Intron 6 of 13		NP_001305754.1	P06865H3BP20B4DVA7
HEXA	NR_134869.3 link	n.714+1G>A	splice_donor_variant, intron_variant	Intron 6 of 10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HEXA	ENST00000268097.10 link	c.672+1G>A		splice_donor_variant, intron_variant	Intron 6 of 13	1	NM_000520.6	ENSP00000268097.6		P06865-1
ENSG00000260729	ENST00000379915.4 link	n.412+4427G>A		intron_variant	Intron 3 of 15	2		ENSP00000478716.1		A0A087WUJ7

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251438

AF XY:

0.00

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:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000488

AC:

AN:

1433838

Hom.:

Cov.:

AF XY:

0.00000699

AC XY:

AN XY:

715296

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

32904

American (AMR)

AF:

0.00

AC:

AN:

44686

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25974

East Asian (EAS)

AF:

0.00

AC:

AN:

39562

South Asian (SAS)

AF:

0.00

AC:

AN:

85692

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53406

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5714

European-Non Finnish (NFE)

AF:

0.00000552

AC:

AN:

1086426

Other (OTH)

AF:

0.0000168

AC:

AN:

59474

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.461

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

Cov.:

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Tay-Sachs disease

Pathogenic:4

Oct 21, 2020

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: HEXA c.672+1G>A is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 5 splicing donor site. Consistent with this prediction, Akli et al report that this variant resulted in skipping of exon 6 and a reduction in HEXA mRNA levels by approximately 50% (Akli_1993). The variant allele was found at a frequency of 4e-06 in 251438 control chromosomes (gnomAD). c.672+1G>A has been reported in the literature in individuals affected with various forms (Juvenile/Adult, Late onset and Infantile acute) of Tay-Sachs Disease (Akli_1993, Maegawa_2007, Tanaka_2003). These data indicate that the variant may be associated with disease. Two ClinVar submitters (evaluation after 2014) cite the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

May 21, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change affects a donor splice site in intron 6 of the HEXA gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in a shortened protein product. This variant is present in population databases (rs387906311, gnomAD 0.0009%). Disruption of this splice site has been observed in individual(s) with clinical features of hexosaminidase A deficiency (PMID: 14566483, 17015493). ClinVar contains an entry for this variant (Variation ID: 3928). Studies have shown that disruption of this splice site results in skipping of exon 6, but is expected to preserve the integrity of the reading-frame (PMID: 8490625). For these reasons, this variant has been classified as Pathogenic. -

May 10, 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. -

Mar 17, 2017

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Tay-sachs disease, juvenile/adult

Pathogenic:1

Jan 01, 1993

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

not provided

Pathogenic:1

Dec 20, 2016

GeneDx

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.672+1 G>A splice site variant in the HEXA gene has been previously reported in a patient with Tay-Sachs disease in whom a second variant in HEXA was not identified (Akli et al. 1993). cDNA and Northern blot analyses found that c.672+1 G>A results in skipping of exon 6 and a 50% reduction in HEXA mRNA levels (Akli et al. 1993). The c.672+1 G> variant was not observed in approximately 6500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. We interpret c.672+1 G> to be a pathogenic variant. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.45

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.1

FATHMM_MKL

Pathogenic

1.0

PhyloP100

7.8

GERP RS

5.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

2.8

Mutation Taster

=0/100

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.94

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.98

Position offset: 1

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

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over