rs753823903

Variant names:

Variant summary

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

The ENST00000511181.5(HEXB):c.-168C>T variant causes a 5 prime UTR premature start codon gain change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000683 in 1,609,522 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 (★★).

Frequency

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

Exomes 𝑓: 0.0000069 ( 0 hom. )

Consequence

HEXB
ENST00000511181.5 5_prime_UTR_premature_start_codon_gain

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 0.713

Publications

2 publications found

Variant links:

Genes affected

HEXB (HGNC:4879): (hexosaminidase subunit beta) Hexosaminidase B is the beta subunit of the lysosomal enzyme beta-hexosaminidase that, together with the cofactor GM2 activator protein, catalyzes the degradation of the ganglioside GM2, and other molecules containing terminal N-acetyl hexosamines. Beta-hexosaminidase is composed of two subunits, alpha and beta, which are encoded by separate genes. Both beta-hexosaminidase alpha and beta subunits are members of family 20 of glycosyl hydrolases. Mutations in the alpha or beta subunit genes lead to an accumulation of GM2 ganglioside in neurons and neurodegenerative disorders termed the GM2 gangliosidoses. Beta subunit gene mutations lead to Sandhoff disease (GM2-gangliosidosis type II). Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2014]

HEXB Gene-Disease associations (from GenCC):

Sandhoff disease
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics, G2P, ClinGen, Genomics England PanelApp, Myriad Women’s Health

HEXB 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

BayesDel_addAF computational evidence supports a deleterious effect, 0.432

PP5

Variant 5-74693701-C-T is Pathogenic according to our data. Variant chr5-74693701-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 281002.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HEXB	NM_000521.4 link	c.508C>T	p.Arg170*	stop_gained	Exon 3 of 14	ENST00000261416.12	NP_000512.2	P07686A0A024RAJ6
HEXB	NM_001292004.2 link	c.-168C>T		5_prime_UTR_premature_start_codon_gain_variant	Exon 3 of 14		NP_001278933.1	P07686Q5URX0
HEXB	NM_001292004.2 link	c.-168C>T		5_prime_UTR_variant	Exon 3 of 14		NP_001278933.1	P07686Q5URX0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HEXB	ENST00000261416.12 link	c.508C>T	p.Arg170*	stop_gained	Exon 3 of 14	1	NM_000521.4	ENSP00000261416.7		P07686

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152152

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

251476

AF XY:

0.0000221

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.0000544

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000686

AC:

AN:

1457370

Hom.:

Cov.:

AF XY:

0.0000110

AC XY:

AN XY:

725388

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33378

American (AMR)

AF:

0.0000224

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26112

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39672

South Asian (SAS)

AF:

0.0000464

AC:

AN:

86134

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53416

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5758

European-Non Finnish (NFE)

AF:

0.00000361

AC:

AN:

1107950

Other (OTH)

AF:

0.00

AC:

AN:

60230

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

AF:

0.00000657

AC:

AN:

152152

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74332

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41442

American (AMR)

AF:

0.0000655

AC:

AN:

15262

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5198

South Asian (SAS)

AF:

0.00

AC:

AN:

4824

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000756

ExAC

AF:

0.0000247

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Sandhoff disease

Pathogenic:5

Sep 19, 2017

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. -

Dec 19, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Aug 02, 2021

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

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: HEXB c.508C>T (p.Arg170X) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory. The variant allele was found at a frequency of 1.6e-05 in 251576 control chromosomes (gnomAD and publication data). c.508C>T has been reported in the literature in one individual affected with Sandhoff Disease (Gort_2012). These data indicate that the variant is very likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. Three ClinVar submitters (evaluation after 2014) cite the variant as pathogenic (n=2) and likely pathogenic (n=1). Based on the evidence outlined above, the variant was classified as likely pathogenic. -

Apr 05, 2024

Fulgent Genetics, Fulgent Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Feb 25, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg170*) in the HEXB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HEXB are known to be pathogenic (PMID: 7550345, 18758829). This variant is present in population databases (rs753823903, gnomAD 0.006%). This premature translational stop signal has been observed in individual(s) with Sandhoff disease (PMID: 22789865). ClinVar contains an entry for this variant (Variation ID: 281002). For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:1

Sep 07, 2016

Eurofins Ntd Llc (ga)

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.43

BayesDel_noAF

Pathogenic

0.55

CADD

Pathogenic

(source)

DANN

Uncertain

1.0

Eigen

Uncertain

0.36

Eigen_PC

Benign

0.15

FATHMM_MKL

Uncertain

0.86

PhyloP100

0.71

Vest4

0.88

GERP RS

1.4

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Mutation Taster

=0/200

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.10

Details are displayed if max score is > 0.2

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

Publications

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rs753823903

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