15-72351207-C-G

Variant names:

• chr15-72351207-C-G
• rs1800429
• NM_000520.6:c.598G>C

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1 PM2 PP3_Strong

The NM_000520.6(HEXA):​c.598G>C​(p.Val200Leu) variant causes a missense change involving the alteration of a conserved nucleotide. 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 nucleotide change resulting in the same amino acid substitution has been previously reported as Uncertain significance in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V200M) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: HEXA NM_000520.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.81
• 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: Myriad Women’s Health, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae), ClinGen

CELF6-AS1 (HGNC:58304):

ENSG00000260729 (HGNC:):

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_000520.6
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.986

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.598G>C	p.Val200Leu	missense	Exon 6 of 14	NP_000511.2
	HEXA	NM_001318825.2		c.631G>C	p.Val211Leu	missense	Exon 6 of 14	NP_001305754.1
	HEXA	NR_134869.3		n.640G>C		non_coding_transcript_exon	Exon 6 of 11

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	HEXA	ENST00000268097.10	TSL:1 MANE Select	c.598G>C	p.Val200Leu	missense	Exon 6 of 14	ENSP00000268097.6
	HEXA	ENST00000567159.5	TSL:1	c.598G>C	p.Val200Leu	missense	Exon 6 of 13	ENSP00000456489.1
	CELF6-AS1	ENST00000570175.1	TSL:1	n.2561C>G		non_coding_transcript_exon	Exon 3 of 3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.65
BayesDel_addAF	Pathogenic	0.55	D
BayesDel_noAF	Pathogenic	0.55
CADD	Pathogenic	26
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.97	D
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.97
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.97	D
M_CAP	Uncertain	0.24	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.7	H
PhyloP100		7.8
PrimateAI	Uncertain	0.64	T
PROVEAN	Uncertain	-2.9	D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0030	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.93
MutPred		0.90		Loss of catalytic residue at V200 (P = 0.0231)
MVP		0.98
MPC		0.74
ClinPred		0.98	D
GERP RS		5.8
Varity_R		0.92
gMVP		0.87
Mutation Taster		=2/98	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

Other links and lift over

dbSNP: rs1800429; hg19: chr15-72643548;