rs199725482

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001478.5(B4GALNT1):​c.254G>T​(p.Ser85Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000217 in 1,614,126 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000021 ( 0 hom. )

Consequence

B4GALNT1
NM_001478.5 missense

Scores

1
18

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 1.20

Publications

1 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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.1231437).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
B4GALNT1NM_001478.5 linkc.254G>T p.Ser85Ile missense_variant Exon 3 of 11 ENST00000341156.9 NP_001469.1 Q00973-1B4DSP5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
B4GALNT1ENST00000341156.9 linkc.254G>T p.Ser85Ile missense_variant Exon 3 of 11 1 NM_001478.5 ENSP00000341562.4 Q00973-1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152138
Hom.:
0
Cov.:
32
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:
0.000193
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000398
AC:
10
AN:
251282
AF XY:
0.0000515
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.000109
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000704
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000212
AC:
31
AN:
1461870
Hom.:
0
Cov.:
32
AF XY:
0.0000179
AC XY:
13
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.0000504
AC:
2
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86256
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000252
AC:
28
AN:
1111994
Other (OTH)
AF:
0.0000166
AC:
1
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.481
Heterozygous variant carriers
0
2
4
7
9
11
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000263
AC:
4
AN:
152256
Hom.:
0
Cov.:
32
AF XY:
0.0000269
AC XY:
2
AN XY:
74450
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41544
American (AMR)
AF:
0.00
AC:
0
AN:
15308
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5178
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4820
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68000
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.563
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<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:
0.0000775
Hom.:
0
Bravo
AF:
0.0000302
ESP6500AA
AF:
0.00
AC:
0
ESP6500EA
AF:
0.000116
AC:
1
ExAC
AF:
0.0000576
AC:
7
EpiCase
AF:
0.000164
EpiControl
AF:
0.000356

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Spastic paraplegia Uncertain:1
Apr 28, 2018
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces serine with isoleucine at codon 85 of the B4GALNT1 protein (p.Ser85Ile). The serine residue is moderately conserved and there is a large physicochemical difference between serine and isoleucine. This variant is present in population databases (rs199725482, ExAC 0.01%). This variant has not been reported in the literature in individuals with B4GALNT1-related disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Inborn genetic diseases Uncertain:1
Oct 06, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.254G>T (p.S85I) alteration is located in exon 3 (coding exon 2) of the B4GALNT1 gene. This alteration results from a G to T substitution at nucleotide position 254, causing the serine (S) at amino acid position 85 to be replaced by an isoleucine (I). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.11
BayesDel_addAF
Benign
-0.26
T
BayesDel_noAF
Benign
-0.41
CADD
Benign
21
DANN
Benign
0.97
DEOGEN2
Benign
0.40
T;T;.;.;.;T
Eigen
Benign
0.0075
Eigen_PC
Benign
-0.0053
FATHMM_MKL
Benign
0.61
D
LIST_S2
Benign
0.83
T;T;.;T;T;T
M_CAP
Benign
0.012
T
MetaRNN
Benign
0.12
T;T;T;T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Uncertain
2.1
M;.;M;M;.;.
PhyloP100
1.2
PrimateAI
Benign
0.35
T
PROVEAN
Benign
-2.1
N;.;N;N;N;D
REVEL
Benign
0.050
Sift
Benign
0.11
T;.;D;D;T;D
Sift4G
Benign
0.14
T;T;D;D;.;.
Polyphen
0.54
P;P;.;.;.;.
Vest4
0.36
MVP
0.70
MPC
0.36
ClinPred
0.16
T
GERP RS
2.9
Varity_R
0.12
gMVP
0.50
Mutation Taster
=92/8
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.10
Details are displayed if max score is > 0.2

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

Publications

Other links and lift over

dbSNP: rs199725482; hg19: chr12-58025112; API