NM_000521.4:c.333G>A

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000521.4(HEXB):c.333G>A(p.Trp111*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000411 in 1,460,782 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

HEXB
NM_000521.4 stop_gained

Scores

Clinical Significance

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

Conservation

PhyloP100: 0.721

Publications

1 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 18 ACMG points.

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 5-74689361-G-A is Pathogenic according to our data. Variant chr5-74689361-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 557986.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.333G>A	p.Trp111*	stop_gained	Exon 2 of 14	ENST00000261416.12	NP_000512.2
HEXB	NM_001292004.2 link	c.-343G>A		5_prime_UTR_variant	Exon 2 of 14		NP_001278933.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
HEXB	ENST00000261416.12 link	c.333G>A	p.Trp111*	stop_gained	Exon 2 of 14	1	NM_000521.4	ENSP00000261416.7
HEXB	ENST00000511181.5 link	c.-343G>A		5_prime_UTR_variant	Exon 2 of 14	1		ENSP00000426285.1
HEXB	ENST00000513079.5 link	n.398G>A		non_coding_transcript_exon_variant	Exon 2 of 6	2
HEXB	ENST00000515528.1 link	n.388G>A		non_coding_transcript_exon_variant	Exon 2 of 2	2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00000795

AC:

AN:

251416

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.0000615

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:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000411

AC:

AN:

1460782

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

726704

show subpopulations

African (AFR)

AF:

0.0000897

AC:

AN:

33454

American (AMR)

AF:

0.00

AC:

AN:

44722

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26122

East Asian (EAS)

AF:

0.00

AC:

AN:

39680

South Asian (SAS)

AF:

0.0000232

AC:

AN:

86236

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53410

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111032

Other (OTH)

AF:

0.0000166

AC:

AN:

60360

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.450

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

Cov.:

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Sandhoff disease

Pathogenic:4

Aug 23, 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.Trp111*) 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 (rs761117459, gnomAD 0.007%). This premature translational stop signal has been observed in individual(s) with Sandhoff disease (PMID: 26582265). ClinVar contains an entry for this variant (Variation ID: 557986). For these reasons, this variant has been classified as Pathogenic.

Apr 25, 2018

Counsyl

Significance: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 26, 2022

Foundation for Research in Genetics and Endocrinology, FRIGE's Institute of Human Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

A compound heterozygous status for the variant c.333G>A in Exon 2 of the HEXB gene was detected. The variants have not been reported in the 1000 genomes database and has a MAF of 0.0008% in the gnomAD database. The in-silico prediction is disease causing by Mutation Taster and DANN. In summary, the variant meets our criteria to be classified as pathogenic.

Feb 06, 2023

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance:Likely pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Uncertain

0.088

BayesDel_noAF

Uncertain

0.070

CADD

Pathogenic

(source)

DANN

Uncertain

0.98

Eigen

Benign

0.15

Eigen_PC

Benign

-0.22

FATHMM_MKL

Benign

0.068

PhyloP100

0.72

Vest4

0.71

GERP RS

0.45

Mutation Taster

=4/196

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.010

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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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