Genetic Variant HEXA:p.Ala246Thr (chr15-72350587-C-T) – ACMG Classification: Pathogenic (20 pts)

Variant summary

Our verdict is Pathogenic. The variant received 20 ACMG points: 20P and 0B. PS3PM1PM2PP3_StrongPP5_Very_Strong

The NM_000520.6(HEXA):c.736G>A(p.Ala246Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,736 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 Likely pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV002051189: The most pronounced variant effect results in <10% of normal activity (Lee_2008).". Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A246S) has been classified as Uncertain significance.

Frequency

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

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

HEXA
NM_000520.6 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 7.81

Publications

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

HEXA links:

CELF6-AS1 (HGNC:58304):

CELF6-AS1 links:

ENSG00000260729 (HGNC:):

ENSG00000260729 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 20 ACMG points.

PS3

PS3 evidence extracted from ClinVar submissions: SCV002051189: The most pronounced variant effect results in <10% of normal activity (Lee_2008).

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 5 uncertain in NM_000520.6

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.991

PP5

Variant 15-72350587-C-T is Pathogenic according to our data. Variant chr15-72350587-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 553250.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 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

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
HEXA	NM_000520.6	MANE Select	c.736G>A	p.Ala246Thr	missense	Exon 7 of 14	NP_000511.2	P06865-1
HEXA	NM_001318825.2		c.769G>A	p.Ala257Thr	missense	Exon 7 of 14	NP_001305754.1	H3BP20
HEXA	NR_134869.3		n.778G>A		non_coding_transcript_exon	Exon 7 of 11

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
HEXA	ENST00000268097.10	TSL:1 MANE Select	c.736G>A	p.Ala246Thr	missense	Exon 7 of 14	ENSP00000268097.6	P06865-1
HEXA	ENST00000567159.5	TSL:1	c.736G>A	p.Ala246Thr	missense	Exon 7 of 13	ENSP00000456489.1	H3BS10
CELF6-AS1	ENST00000570175.1	TSL:1	n.1941C>T		non_coding_transcript_exon	Exon 3 of 3

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152190

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:

0.000207

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251482

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:

0.00000411

AC:

AN:

1461546

Hom.:

Cov.:

AF XY:

0.00000413

AC XY:

AN XY:

727086

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33466

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26130

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86248

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53414

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5756

European-Non Finnish (NFE)

AF:

0.00000540

AC:

AN:

1111730

Other (OTH)

AF:

0.00

AC:

AN:

60382

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.533

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:

0.00000657

AC:

AN:

152190

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74350

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41440

American (AMR)

AF:

0.00

AC:

AN:

15280

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3464

East Asian (EAS)

AF:

0.00

AC:

AN:

5198

South Asian (SAS)

AF:

0.000207

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10620

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

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:

0.00

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.00000824

AC:

ClinVar

ClinVar submissions

Significance:Pathogenic/Likely pathogenic

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Tay-Sachs disease (5)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.81

BayesDel_addAF

Pathogenic

0.58

BayesDel_noAF

Pathogenic

0.59

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.98

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

1.0

M_CAP

Pathogenic

0.40

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

0.96

MutationAssessor

Pathogenic

4.4

PhyloP100

7.8

PrimateAI

Uncertain

0.61

PROVEAN

Uncertain

-3.8

REVEL

Pathogenic

0.95

Sift

Uncertain

0.0020

Sift4G

Uncertain

0.0030

Polyphen

1.0

Vest4

0.93

MutPred

0.97

Loss of methylation at R247 (P = 0.0934)

MVP

1.0

MPC

0.74

ClinPred

1.0

GERP RS

5.9

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.93

gMVP

0.95

Mutation Taster

=1/99

disease causing

(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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over