Genetic Variant NM_000520.6:c.1361G>A (chr15-72346295-C-T) – ACMG Classification: Pathogenic (15 pts)

Variant summary

Our verdict is . The variant received 15 ACMG points: 15P and 0B. PS3PM1PM2PM5PP3_StrongPP5

The NM_000520.6(HEXA):c.1361G>A(p.Gly454Asp) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,786 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). ClinVar reports functional evidence for this variant: "SCV003002399: Experimental studies have shown that this missense change affects HEXA function (PMID:12689698).". Another variant affecting the same amino acid position, but resulting in a different missense (i.e. G454R) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

HEXA
NM_000520.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:2

Conservation

PhyloP100: 7.81

Publications

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

HEXA links:

ENSG00000260729 (HGNC:):

ENSG00000260729 links:

CELF6-AS1 (HGNC:58304):

CELF6-AS1 links:

Genome browser will be placed here

new If you want to explore the variant's impact on the transcript NM_000520.6, check out the Mutation Effect Viewer. This is especially useful for frameshift variants or if you want to visualize the effect of exon loss / intron retention.

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 15 ACMG points.

PS3

PS3 evidence extracted from ClinVar submissions: SCV003002399: Experimental studies have shown that this missense change affects HEXA function (PMID: 12689698).

PM1

In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 uncertain in NM_000520.6

PM2

Very rare variant in population databases, with high coverage;

PM5

Other missense variant is known to change same aminoacid residue: Variant chr15-72346296-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 375363.Status of the report is no_assertion_criteria_provided, 0 stars.

PP3

REVEL computational evidence supports a deleterious effect, 0.973

PP5

Variant 15-72346295-C-T is Pathogenic according to our data. Variant chr15-72346295-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 555211.

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.1361G>A	p.Gly454Asp	missense	Exon 12 of 14	NP_000511.2	P06865-1
HEXA	NM_001318825.2		c.1394G>A	p.Gly465Asp	missense	Exon 12 of 14	NP_001305754.1	H3BP20
HEXA	NR_134869.3		n.1146G>A		non_coding_transcript_exon	Exon 10 of 11

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
HEXA	ENST00000268097.10	TSL:1 MANE Select	c.1361G>A	p.Gly454Asp	missense	Exon 12 of 14	ENSP00000268097.6	P06865-1
HEXA	ENST00000567159.5	TSL:1	c.1361G>A	p.Gly454Asp	missense	Exon 12 of 13	ENSP00000456489.1	H3BS10
ENSG00000260729	ENST00000379915.4	TSL:2	n.443G>A		non_coding_transcript_exon	Exon 4 of 16	ENSP00000478716.1	A0A087WUJ7

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461786

Hom.:

Cov.:

AF XY:

0.00000138

AC XY:

AN XY:

727200

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33476

American (AMR)

AF:

0.00

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26132

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86250

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

8.99e-7

AC:

AN:

1111934

Other (OTH)

AF:

0.00

AC:

AN:

60392

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

GnomAD4 genome

Cov.:

ClinVar

ClinVar submissions

Significance:Conflicting classifications of pathogenicity

Revision:criteria provided, conflicting classifications

View on ClinVar

Pathogenic

VUS

Benign

Condition

Tay-Sachs disease (4)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.99

BayesDel_addAF

Pathogenic

0.58

BayesDel_noAF

Pathogenic

0.59

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.99

Eigen

Pathogenic

0.89

Eigen_PC

Pathogenic

0.76

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.90

M_CAP

Pathogenic

0.62

MetaRNN

Pathogenic

0.99

MetaSVM

Pathogenic

0.88

MutationAssessor

Pathogenic

4.2

PhyloP100

7.8

PrimateAI

Pathogenic

0.84

PROVEAN

Pathogenic

-6.6

REVEL

Pathogenic

0.97

Sift

Pathogenic

0.0

Sift4G

Pathogenic

0.0

RBP_binding_hub_radar

0.97

RBP_regulation_power_radar

2.7

Varity_R

0.98

gMVP

0.99

Mutation Taster

=2/98

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

MaxEntScan Visualizer can be used to analyze the impact of this mutation on the neighboring sequence.

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over