15-72350578-G-A

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2PP3_Moderate

The NM_000520.6(HEXA):c.745C>T(p.Arg249Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000274 in 1,614,120 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 Conflicting classifications of pathogenicity,other (no stars).

Frequency

Genomes: 𝑓 0.00020 ( 0 hom., cov: 32)

Exomes 𝑓: 0.00028 ( 0 hom. )

Consequence

HEXA
NM_000520.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity; other criteria provided, conflicting classifications U:1B:1O:3

Conservation

PhyloP100: 2.11

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 links:

ENSG00000261460 (HGNC:58304):

ENSG00000261460 links:

ENSG00000260729 (HGNC:):

ENSG00000260729 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 4 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.927

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HEXA	NM_000520.6 link	c.745C>T	p.Arg249Trp	missense_variant	Exon 7 of 14	ENST00000268097.10	NP_000511.2	P06865-1A0A0S2Z3W3
HEXA	NM_001318825.2 link	c.778C>T	p.Arg260Trp	missense_variant	Exon 7 of 14		NP_001305754.1	P06865H3BP20B4DVA7
HEXA	NR_134869.3 link	n.787C>T		non_coding_transcript_exon_variant	Exon 7 of 11

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
HEXA	ENST00000268097.10 link	c.745C>T	p.Arg249Trp	missense_variant	Exon 7 of 14	1	NM_000520.6	ENSP00000268097.6		P06865-1
ENSG00000260729	ENST00000379915.4 link	n.413-4253C>T		intron_variant	Intron 3 of 15	2		ENSP00000478716.1		A0A087WUJ7

Frequencies

GnomAD3 genomes

AF:

0.000204

AC:

AN:

152174

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000121

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00135

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000279

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.000191

AC:

AN:

251478

Hom.:

AF XY:

0.000199

AC XY:

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.000123

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000707

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000290

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.000282

AC:

412

AN:

1461828

Hom.:

Cov.:

AF XY:

0.000272

AC XY:

198

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.000149

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000579

Gnomad4 SAS exome

AF:

0.0000348

Gnomad4 FIN exome

AF:

0.0000187

Gnomad4 NFE exome

AF:

0.000304

Gnomad4 OTH exome

AF:

0.000696

GnomAD4 genome

AF:

0.000204

AC:

AN:

152292

Hom.:

Cov.:

AF XY:

0.000188

AC XY:

AN XY:

74482

show subpopulations

Gnomad4 AFR

AF:

0.000120

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00135

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000279

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000333

Hom.:

Bravo

AF:

0.000246

TwinsUK

AF:

0.000270

AC:

ALSPAC

AF:

0.00

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000582

AC:

ExAC

AF:

0.000231

AC:

Asia WGS

AF:

0.000577

AC:

AN:

3478

EpiCase

AF:

0.000600

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity; other

Submissions summary: Uncertain:1Benign:1Other:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:1Benign:1Other:1

Aug 11, 2016

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

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: The HEXA c.745C>T (p.Arg249Trp) variant causes a missense change involving a conserved nucleotide with 5/5 in silico tools predicting a damaging outcome. The variant of interest was found in the large, broad control population, ExAC, with an allele frequency of 28/121408 (1/4336), which does not exceed the estimated maximal expected allele frequency for a pathogenic HEXA variant of 1/715. The variant of interest is known to be a common pseudodeficiency allele, which is not associated with neurologic disease but is associated wtih reduced degradation of the synthetic substrate when HEX A enzymatic activity is determined (Gene Reviews). Therefore, the variant of interest is classified as Benign. -

Feb 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

HEXA: PM2:Supporting -

Jul 19, 2016

Eurofins Ntd Llc (ga)

Significance: other

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- Variant classified as "other reportable" ??? variant is clinically benign (not associated with disease) but is reported when observed (e.g. pseudodeficiency alleles).

Tay-Sachs disease

Other:2

Dec 13, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: other

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- pseudodeficiency allele

May 30, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: other

Review Status: criteria provided, single submitter

Collection Method: clinical testing

pseudodeficiency The Arg249Trp variant in HEXA is a well-established pseudodeficiency allele for HEXA activity (Cao 1993) and has been identified in 0.05% (5/8594) of European American chromosomes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/; dbSNP rs138058578). The Arg249Trp variant is clinically benign (i.e., has normal activity in vivo) but has reduced HEXA enzyme activity toward synthetic substrates and therefore can produce a false positive result on enzyme analysis, a technique often used for carrier screening (Hoffman 2013).

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.40

BayesDel_addAF

Pathogenic

0.28

BayesDel_noAF

Pathogenic

0.53

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.98

D;.;D

Eigen

Uncertain

0.65

Eigen_PC

Uncertain

0.55

FATHMM_MKL

Uncertain

0.94

LIST_S2

Uncertain

0.96

D;D;D

M_CAP

Uncertain

0.25

MetaRNN

Pathogenic

0.93

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

3.9

H;.;.

PrimateAI

Uncertain

0.64

PROVEAN

Pathogenic

-7.8

D;D;D

REVEL

Pathogenic

0.93

Sift

Pathogenic

0.0

D;D;D

Sift4G

Pathogenic

0.0

D;D;D

Polyphen

1.0

D;.;.

Vest4

0.88

MVP

1.0

MPC

0.73

ClinPred

0.95

GERP RS

5.0

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.1

Varity_R

0.92

gMVP

0.97

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.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over