rs267606862

chr15-72346681-C-T

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_000520.6(HEXA):c.1176G>A(p.Trp392Ter) variant causes a stop gained change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,838 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 Pathogenic (★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 30)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: HEXA NM_000520.6 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1 O:1
• Conservation: PhyloP100: 7.78

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]

(HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 12 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 15-72346681-C-T is Pathogenic according to our data. Variant chr15-72346681-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 3936.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
HEXA	NM_000520.6	c.1176G>A	p.Trp392Ter	stop_gained	11/14	ENST00000268097.10
HEXA	NM_001318825.2	c.1209G>A	p.Trp403Ter	stop_gained	11/14
HEXA	NR_134869.3	n.1116-356G>A		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
HEXA	ENST00000268097.10	c.1176G>A	p.Trp392Ter	stop_gained	11/14	1	NM_000520.6	P1
	ENST00000570175.1	n.1461C>T		non_coding_transcript_exon_variant	2/3	1

Frequencies

GnomAD3 genomes Cov.: 30

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461838 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727218

Gnomad4 AFR exome AF: 0.0000299

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 30

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: criteria provided, single submitter

Submissions by phenotype

Tay-Sachs disease Pathogenic:1 Other:1

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Nov 17, 2023	This sequence change creates a premature translational stop signal (p.Trp392*) in the HEXA gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in HEXA are known to be pathogenic (PMID: 1833974, 8490625). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with Tay-Sachs disease (PMID: 1301958). ClinVar contains an entry for this variant (Variation ID: 3936). For these reasons, this variant has been classified as Pathogenic. -
Affects, no assertion criteria provided	literature only	OMIM	Jan 01, 1992	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.66
Cadd	Pathogenic	38
Dann	Uncertain	1.0
Eigen	Pathogenic	0.94
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	1.0	D
MutationTaster	Benign	1.0	A;A;A;A;D
Vest4		0.98
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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

LitVar

Other links and lift over

dbSNP: rs267606862; hg19: chr15-72639022;