Variant 12-57626900-A-AT details in Genebe, Genetics Data Aggregator

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_StrongPM2PP5_Moderate

The NM_001478.5(B4GALNT1):c.1445_1446insA(p.Asp482GlufsTer82) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,170 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Consequence

B4GALNT1
NM_001478.5 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, single submitter P:1

Conservation

PhyloP100: 3.08

Variant links:

Genes affected

B4GALNT1 (HGNC:4117): (beta-1,4-N-acetyl-galactosaminyltransferase 1) GM2 and GD2 gangliosides are sialic acid-containing glycosphingolipids. GalNAc-T is the enzyme involved in the biosynthesis of G(M2) and G(D2) glycosphingolipids. GalNAc-T catalyzes the transfer of GalNAc into G(M3) and G(D3) by a beta-1,4 linkage, resulting in the synthesis of G(M2) and G(D2), respectively. Three transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Feb 2013]

B4GALNT1 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PVS1

Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 12-57626900-A-AT is Pathogenic according to our data. Variant chr12-57626900-A-AT is described in ClinVar as [Pathogenic]. Clinvar id is 852385.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
B4GALNT1	NM_001478.5 linkuse as main transcript	c.1445_1446insA	p.Asp482GlufsTer82	frameshift_variant	11/11	ENST00000341156.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
B4GALNT1	ENST00000341156.9 linkuse as main transcript	c.1445_1446insA	p.Asp482GlufsTer82	frameshift_variant	11/11	1	NM_001478.5	P1	Q00973-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152170

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152170

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74354

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

LINK: link

Submissions by phenotype

Spastic paraplegia

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 08, 2019

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the C-terminus of the B4GALNT1 protein. Other variant(s) that disrupt this region (p.Leu487Thrfs*77) have been determined to be pathogenic (PMID: 24283893, 24103911). This suggests that variants that disrupt this region of the protein are likely to be causative of disease. Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the affected amino acid(s) is currently unknown. This variant has not been reported in the literature in individuals with B4GALNT1-related conditions. This variant is not present in population databases (ExAC no frequency). This sequence change results in a premature translational stop signal in the B4GALNT1 gene (p.Asp482Glufs*82). While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 52 amino acids of the B4GALNT1 protein. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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