NM_001478.5:c.682C>T

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_001478.5(B4GALNT1):c.682C>T(p.Arg228*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000372 in 1,614,038 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 (★★). Synonymous variant affecting the same amino acid position (i.e. R228R) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000034 ( 0 hom. )

Consequence

B4GALNT1
NM_001478.5 stop_gained

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:5

Conservation

PhyloP100: 1.28

Publications

3 publications found

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 Gene-Disease associations (from GenCC):

complex hereditary spastic paraplegia
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
hereditary spastic paraplegia 26
Inheritance: AR Classification: STRONG, MODERATE, SUPPORTIVE Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), Orphanet

B4GALNT1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 18 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 12-57630182-G-A is Pathogenic according to our data. Variant chr12-57630182-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 60524.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
B4GALNT1	NM_001478.5 link	c.682C>T	p.Arg228*	stop_gained	Exon 6 of 11	ENST00000341156.9	NP_001469.1	Q00973-1B4DSP5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
B4GALNT1	ENST00000341156.9 link	c.682C>T	p.Arg228*	stop_gained	Exon 6 of 11	1	NM_001478.5	ENSP00000341562.4		Q00973-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152168

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251410

AF XY:

0.00

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000289

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000342

AC:

AN:

1461870

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727226

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.0000224

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39698

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1111998

Other (OTH)

AF:

0.00

AC:

AN:

60394

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.485

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152168

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74338

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41422

American (AMR)

AF:

0.0000655

AC:

AN:

15276

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5202

South Asian (SAS)

AF:

0.00

AC:

AN:

4834

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10612

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68032

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Hereditary spastic paraplegia 26

Pathogenic:4

Paris Brain Institute, Inserm - ICM

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Oct 18, 2021

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

ACMG classification criteria: PVS1 very strong, PS3 supporting, PS4 supporting, PM2 moderate, PM3 moderate, PP1 strong -

Jul 11, 2013

OMIM

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:literature only

- -

Nov 15, 2018

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:research

The homozygous p.Arg228Ter variant in B4GALNT1 was identified by our study in one individual with Spastic Paraplegia. This variant has been reported as homozygous in the literature in two affected family members (Boukhris et al. 2013; PMID: 23746551). This variant has been identified in <0.01% (1/33582) of Latino chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs398122382). Although this variant has been seen in the general population, its frequency is low enough to be consistent with a recessive carrier frequency. Loss of function of the B4GALNT1 gene is an established disease mechanism in autosomal recessive Spastic Paraplegia, and this is a loss of function variant. In summary, this variant is pathogenic. -

Spastic paraplegia

Pathogenic:1

May 22, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Arg228*) in the B4GALNT1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in B4GALNT1 are known to be pathogenic (PMID: 23746551). This variant is present in population databases (rs398122382, gnomAD 0.003%). This premature translational stop signal has been observed in individual(s) with hereditary spastic paraplegia (PMID: 23746551). ClinVar contains an entry for this variant (Variation ID: 60524). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.13

BayesDel_addAF

Pathogenic

0.57

BayesDel_noAF

Pathogenic

0.43

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

Eigen

Uncertain

0.52

Eigen_PC

Uncertain

0.29

FATHMM_MKL

Uncertain

0.80

PhyloP100

1.3

Vest4

0.35

GERP RS

0.47

Mutation Taster

=8/192

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.020

Details are displayed if max score is > 0.2

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over