15-72356524-C-G

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_ModeratePM2PP3_StrongPP5_Very_Strong

The NM_000520.6(HEXA):c.346+1G>C variant causes a splice donor change. The variant allele was found at a frequency of 0.00000124 in 1,613,906 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★★).

Frequency

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

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

HEXA
NM_000520.6 splice_donor

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4O:1

Conservation

PhyloP100: 4.71

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.057861634 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.1, offset of -36, new splice context is: gatGTaacc. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 15-72356524-C-G is Pathogenic according to our data. Variant chr15-72356524-C-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3893.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	Effect	MANE
HEXA	NM_000520.6 linkuse as main transcript	c.346+1G>C	splice_donor_variant	ENST00000268097.10
HEXA	NM_001318825.2 linkuse as main transcript	c.379+1G>C	splice_donor_variant
HEXA	NR_134869.3 linkuse as main transcript	n.388+1G>C	splice_donor_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HEXA	ENST00000268097.10 linkuse as main transcript	c.346+1G>C		splice_donor_variant		1	NM_000520.6	P1	P06865-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152188

Hom.:

Cov.:

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

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461718

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727164

show subpopulations

Gnomad4 AFR exome

AF:

0.0000299

Gnomad4 AMR exome

AF:

0.00

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152188

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74334

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

Bravo

AF:

0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Tay-Sachs disease

Pathogenic:4Other:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	May 17, 2016	- -
Pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Mar 17, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Jun 09, 2016	Variant summary: The HEXA c.346+1G>C variant involves the alteration of a conserved intronic nucleotide with 5/5 splice prediction tools predicting a significant impact on splicing. The variant of interest was not observed in controls (ExAC, 1000 Gs or ESP), but has been reported in an affected individual with infantile Tay-Sachs disease, along with a reputable database citing the variant as "pathogenic." Therefore, the variant of interest is classified as Pathogenic. -
Affects, no assertion criteria provided	literature only	OMIM	Nov 01, 1991	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 21, 2023	This sequence change affects a donor splice site in intron 2 of the HEXA gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in HEXA are known to be pathogenic (PMID: 1833974, 8490625). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with clinical features of hexosaminidase A deficiency (PMID: 1833974, 1837283, 34554397). ClinVar contains an entry for this variant (Variation ID: 3893). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.63

BayesDel_noAF

Pathogenic

0.14

Cadd

Pathogenic

Dann

Uncertain

0.99

Eigen

Pathogenic

0.97

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.98

MutationTaster

Benign

1.0

D;D;D;D;D

GERP RS

5.3

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.91

SpliceAI score (max)

0.92

Details are displayed if max score is > 0.2

DS_DL_spliceai

0.92

Position offset: 1

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over