rs768438206

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_000521.4(HEXB):​c.965delT​(p.Ile322fs) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,612,362 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: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

HEXB
NM_000521.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:3

Conservation

PhyloP100: 8.01
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 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 5-74715572-AT-A is Pathogenic according to our data. Variant chr5-74715572-AT-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 557437.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect #exon/exons MANE Protein UniProt
HEXBNM_000521.4 linkuse as main transcriptc.965delT p.Ile322fs frameshift_variant 8/14 ENST00000261416.12 NP_000512.2 P07686A0A024RAJ6
HEXBNM_001292004.2 linkuse as main transcriptc.290delT p.Ile97fs frameshift_variant 8/14 NP_001278933.1 P07686Q5URX0

Ensembl

Gene Transcript HGVSc HGVSp Effect #exon/exons TSL MANE Protein Appris UniProt
HEXBENST00000261416.12 linkuse as main transcriptc.965delT p.Ile322fs frameshift_variant 8/141 NM_000521.4 ENSP00000261416.7 P07686
HEXBENST00000511181.5 linkuse as main transcriptc.290delT p.Ile97fs frameshift_variant 8/141 ENSP00000426285.1 Q5URX0
HEXBENST00000504459.5 linkuse as main transcriptn.162delT non_coding_transcript_exon_variant 2/73
HEXBENST00000513336.5 linkuse as main transcriptc.-14delT upstream_gene_variant 3 ENSP00000423713.1 H0Y9B6

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
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:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD3 exomes
AF:
0.00000398
AC:
1
AN:
251424
Hom.:
0
AF XY:
0.00
AC XY:
0
AN XY:
135890
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 SAS 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:
6.85e-7
AC:
1
AN:
1460170
Hom.:
0
Cov.:
29
AF XY:
0.00
AC XY:
0
AN XY:
726556
show subpopulations
Gnomad4 AFR exome
AF:
0.00
Gnomad4 AMR exome
AF:
0.00
Gnomad4 ASJ exome
AF:
0.00
Gnomad4 EAS exome
AF:
0.00
Gnomad4 SAS exome
AF:
0.00
Gnomad4 FIN exome
AF:
0.00
Gnomad4 NFE exome
AF:
9.01e-7
Gnomad4 OTH exome
AF:
0.00
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152192
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74350
show subpopulations
Gnomad4 AFR
AF:
0.00
Gnomad4 AMR
AF:
0.00
Gnomad4 ASJ
AF:
0.00
Gnomad4 EAS
AF:
0.00
Gnomad4 SAS
AF:
0.00
Gnomad4 FIN
AF:
0.00
Gnomad4 NFE
AF:
0.0000147
Gnomad4 OTH
AF:
0.00

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:3
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Sandhoff disease Pathogenic:2
Likely pathogenic, criteria provided, single submitterclinical testingCounsylMar 30, 2018- -
Pathogenic, criteria provided, single submitterclinical testingLabcorp Genetics (formerly Invitae), LabcorpOct 31, 2018Loss-of-function variants in HEXB are known to be pathogenic (PMID: 7550345, 18758829). For these reasons, this variant has been classified as Pathogenic. This variant has been observed to segregate with Sandhoff disease in a family (PMID: 18758829). ClinVar contains an entry for this variant (Variation ID: 557437). This variant is present in population databases (rs768438206, ExAC 0.001%). This sequence change creates a premature translational stop signal (p.Ile322Lysfs*5) in the HEXB gene. It is expected to result in an absent or disrupted protein product. -
Sandhoff disease, infantile form Pathogenic:1
Pathogenic, no assertion criteria providedliterature onlyOMIMFeb 01, 2009- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction

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

LitVar

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs768438206; hg19: chr5-74011397; API