NM_000521.4:c.715G>A

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM1

The NM_000521.4(HEXB):​c.715G>A​(p.Val239Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000854 in 1,612,542 control chromosomes in the GnomAD database, including 1 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00049 ( 0 hom., cov: 33)
Exomes 𝑓: 0.00089 ( 1 hom. )

Consequence

HEXB
NM_000521.4 missense

Scores

7
7
3

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:10

Conservation

PhyloP100: 9.52

Publications

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 4 uncertain in NM_000521.4

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000521.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
HEXB
NM_000521.4
MANE Select
c.715G>Ap.Val239Ile
missense
Exon 6 of 14NP_000512.2P07686
HEXB
NM_001292004.2
c.40G>Ap.Val14Ile
missense
Exon 6 of 14NP_001278933.1Q5URX0

Ensembl Transcripts

Sel.
GeneTranscriptTagsHGVScHGVSpEffectExon RankProteinUniProt
HEXB
ENST00000261416.12
TSL:1 MANE Select
c.715G>Ap.Val239Ile
missense
Exon 6 of 14ENSP00000261416.7P07686
HEXB
ENST00000511181.5
TSL:1
c.40G>Ap.Val14Ile
missense
Exon 6 of 14ENSP00000426285.1Q5URX0
HEXB
ENST00000513079.5
TSL:2
n.780G>A
non_coding_transcript_exon
Exon 6 of 6

Frequencies

GnomAD3 genomes
AF:
0.000486
AC:
74
AN:
152144
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000193
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.000262
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:
0.000897
Gnomad OTH
AF:
0.000478
GnomAD2 exomes
AF:
0.000362
AC:
91
AN:
251376
AF XY:
0.000353
show subpopulations
Gnomad AFR exome
AF:
0.0000615
Gnomad AMR exome
AF:
0.000202
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.000704
Gnomad OTH exome
AF:
0.000489
GnomAD4 exome
AF:
0.000892
AC:
1303
AN:
1460280
Hom.:
1
Cov.:
29
AF XY:
0.000892
AC XY:
648
AN XY:
726562
show subpopulations
African (AFR)
AF:
0.0000598
AC:
2
AN:
33458
American (AMR)
AF:
0.000134
AC:
6
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39640
South Asian (SAS)
AF:
0.0000928
AC:
8
AN:
86228
European-Finnish (FIN)
AF:
0.0000187
AC:
1
AN:
53368
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5760
European-Non Finnish (NFE)
AF:
0.00113
AC:
1257
AN:
1110636
Other (OTH)
AF:
0.000481
AC:
29
AN:
60348
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.450
Heterozygous variant carriers
0
61
122
184
245
306
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
48
96
144
192
240
<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:
0.000486
AC:
74
AN:
152262
Hom.:
0
Cov.:
33
AF XY:
0.000457
AC XY:
34
AN XY:
74448
show subpopulations
African (AFR)
AF:
0.000192
AC:
8
AN:
41566
American (AMR)
AF:
0.000262
AC:
4
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5190
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.000897
AC:
61
AN:
68006
Other (OTH)
AF:
0.000473
AC:
1
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.491
Heterozygous variant carriers
0
4
8
13
17
21
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.000859
Hom.:
0
Bravo
AF:
0.000457
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.00130
AC:
5
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.00105
AC:
9
ExAC
AF:
0.000305
AC:
37
EpiCase
AF:
0.000872
EpiControl
AF:
0.000948

ClinVar

ClinVar submissions
Significance:Uncertain significance
Revision:criteria provided, multiple submitters, no conflicts
View on ClinVar
Pathogenic
VUS
Benign
Condition
-
6
-
Sandhoff disease (6)
-
3
-
not provided (3)
-
1
-
not specified (1)

Computational scores

Source: dbNSFP v4.9

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.14
BayesDel_addAF
Benign
-0.036
T
BayesDel_noAF
Uncertain
0.13
CADD
Uncertain
24
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.67
D
Eigen
Pathogenic
0.84
Eigen_PC
Pathogenic
0.76
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Pathogenic
0.98
D
M_CAP
Pathogenic
0.29
D
MetaRNN
Uncertain
0.65
D
MetaSVM
Pathogenic
1.1
D
PhyloP100
9.5
PrimateAI
Uncertain
0.55
T
PROVEAN
Benign
-0.98
N
REVEL
Pathogenic
0.67
Sift
Uncertain
0.0030
D
Sift4G
Uncertain
0.022
D
Vest4
0.71
MVP
0.87
MPC
0.55
ClinPred
0.16
T
GERP RS
5.8
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
gMVP
0.71
Mutation Taster
=15/85
disease causing

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

Other links and lift over

dbSNP: rs145056714; hg19: chr5-74001089; COSMIC: COSV54670087; COSMIC: COSV54670087; API