rs1057521137

Variant names:

• chr15-72350575-C-G
• rs1057521137
• NM_000520.6:c.748G>C

Your query was ambiguous. Multiple possible variants found:

• chr15-72350575-C-G
• chr15-72350575-C-T

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.748G>C​(p.Gly250Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,712 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. G250S) has been classified as Likely pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: HEXA NM_000520.6 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 7.81

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]

ENSG00000261460 (HGNC:58304):

ENSG00000260729 (HGNC:):

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 2 benign, 6 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 chr15-72350574-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3902.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
HEXA	NM_000520.6	c.748G>C	p.Gly250Arg	missense_variant	Exon 7 of 14	ENST00000268097.10	NP_000511.2
HEXA	NM_001318825.2	c.781G>C	p.Gly261Arg	missense_variant	Exon 7 of 14		NP_001305754.1
HEXA	NR_134869.3	n.790G>C		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	c.748G>C	p.Gly250Arg	missense_variant	Exon 7 of 14	1	NM_000520.6	ENSP00000268097.6
ENSG00000260729	ENST00000379915.4	n.413-4250G>C		intron_variant	Intron 3 of 15	2		ENSP00000478716.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461712 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727166

Gnomad4 AFR exome AF: 0.00 AC: 0 AN: 33472

Gnomad4 AMR exome AF: 0.00 AC: 0 AN: 44724

Gnomad4 ASJ exome AF: 0.00 AC: 0 AN: 26132

Gnomad4 EAS exome AF: 0.00 AC: 0 AN: 39700

Gnomad4 SAS exome AF: 0.00 AC: 0 AN: 86256

Gnomad4 FIN exome AF: 0.00 AC: 0 AN: 53416

Gnomad4 NFE exome AF: 8.99e-7 AC: 1 AN: 1111888

Gnomad4 Remaining exome AF: 0.00 AC: 0 AN: 60378

⚠️ The allele balance in gnomAD4 Exomes is highly skewed (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.61
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.98	D;.;D
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	1.0	D;D;D
M_CAP	Uncertain	0.28	D
MetaRNN	Pathogenic	0.99	D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.3	H;.;.
PrimateAI	Uncertain	0.76	T
PROVEAN	Pathogenic	-7.8	D;D;D
REVEL	Pathogenic	0.96
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		1.0	D;.;.
Vest4		0.97
MutPred		0.91		Gain of solvent accessibility (P = 0.019);.;Gain of solvent accessibility (P = 0.019);
MVP		1.0
MPC		0.82
ClinPred		1.0	D
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
gMVP		0.95
Mutation Taster		=1/99	disease causing

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: rs1057521137; hg19: chr15-72642916;