15-72345477-G-C

Variant names:

• chr15-72345477-G-C
• rs121907966
• NM_000520.6:c.1495C>G

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PM1 PM2 PM5 PP3_Strong

The NM_000520.6(HEXA):​c.1495C>G​(p.Arg499Gly) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R499C) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 34)
• Consequence: HEXA NM_000520.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 5.17
• Publications: 0 publications found

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 Gene-Disease associations (from GenCC):

• Tay-Sachs disease

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Myriad Women’s Health, Labcorp Genetics (formerly Invitae), Genomics England PanelApp, G2P

ENSG00000260729 (HGNC:):

CELF6-AS1 (HGNC:58304):

ACMG classification

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 uncertain in NM_000520.6
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr15-72345477-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 3915.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.99

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000520.6. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HEXA	NM_000520.6	MANE Select	c.1495C>G	p.Arg499Gly	missense	Exon 13 of 14	NP_000511.2	P06865-1
	HEXA	NM_001318825.2		c.1528C>G	p.Arg510Gly	missense	Exon 13 of 14	NP_001305754.1	H3BP20
	HEXA	NR_134869.3		n.1280C>G		non_coding_transcript_exon	Exon 11 of 11

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HEXA	ENST00000268097.10	TSL:1 MANE Select	c.1495C>G	p.Arg499Gly	missense	Exon 13 of 14	ENSP00000268097.6	P06865-1
	HEXA	ENST00000567159.5	TSL:1	c.1495C>G	p.Arg499Gly	missense	Exon 13 of 13	ENSP00000456489.1	H3BS10
	ENSG00000260729	ENST00000379915.4	TSL:2	n.577C>G		non_coding_transcript_exon	Exon 5 of 16	ENSP00000478716.1	A0A087WUJ7

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 34

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.96
BayesDel_addAF	Pathogenic	0.56	D
BayesDel_noAF	Pathogenic	0.57
CADD	Pathogenic	29
DANN	Uncertain	0.99
DEOGEN2	Pathogenic	0.96	D
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Benign	0.85	D
M_CAP	Uncertain	0.21	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.7	H
PhyloP100		5.2
PrimateAI	Benign	0.48	T
PROVEAN	Pathogenic	-6.5	D
REVEL	Pathogenic	0.89
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.96
MutPred		0.95		Loss of stability (P = 0.0272)
MVP		1.0
MPC		0.85
ClinPred		1.0	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.94
gMVP		0.98

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.20		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.20		Position offset: 0

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs121907966; hg19: chr15-72637818;