15-72353179-C-T

Variant names:

• chr15-72353179-C-T
• rs764343937
• NM_000520.6:c.460-1G>A

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PVS1_Moderate PM2 PP5

The NM_000520.6(HEXA):​c.460-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: HEXA NM_000520.6 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.81
• Publications: 1 publications found

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: ClinGen, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P

ENSG00000260729 (HGNC:):

ACMG classification

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.06981132 fraction of the gene. Cryptic splice site detected, with MaxEntScore 7.3, offset of -45, new splice context is: atctccctgtgcccccatAGtaa. 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
• PP5: Variant 15-72353179-C-T is Pathogenic according to our data. Variant chr15-72353179-C-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 375352.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000520.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HEXA	NM_000520.6	MANE Select	c.460-1G>A		splice_acceptor intron	N/A	NP_000511.2	P06865-1
	HEXA	NM_001318825.2		c.493-1G>A		splice_acceptor intron	N/A	NP_001305754.1	H3BP20
	HEXA	NR_134869.3		n.502-1G>A		splice_acceptor intron	N/A

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HEXA	ENST00000268097.10	TSL:1 MANE Select	c.460-1G>A		splice_acceptor intron	N/A	ENSP00000268097.6	P06865-1
	HEXA	ENST00000567159.5	TSL:1	c.460-1G>A		splice_acceptor intron	N/A	ENSP00000456489.1	H3BS10
	ENSG00000260729	ENST00000379915.4	TSL:2	n.412+2380G>A		intron	N/A	ENSP00000478716.1	A0A087WUJ7

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1418680 Hom.: 0 Cov.: 25 AF XY: 0.00 AC XY: 0 AN XY: 708332

African (AFR) AF: 0.00 AC: 0 AN: 32598

American (AMR) AF: 0.00 AC: 0 AN: 44498

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25834

East Asian (EAS) AF: 0.00 AC: 0 AN: 39452

South Asian (SAS) AF: 0.00 AC: 0 AN: 85066

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53290

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5666

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1073344

Other (OTH) AF: 0.00 AC: 0 AN: 58932

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Likely pathogenic

Revision: no assertion criteria provided

Pathogenic	VUS	Benign	Condition
1	-	-	Tay-Sachs disease (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	30
DANN	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		7.8
GERP RS		5.4
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.92		Details are displayed if max score is > 0.2
DS_AL_spliceai		0.92		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs764343937; hg19: chr15-72645520;