20-763738-G-C

Variant summary

Our verdict is Likely benign. The variant received -5 ACMG points: 0P and 5B. BP4_StrongBS1_Supporting

The NM_033409.4(SLC52A3):​c.833C>G​(p.Thr278Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,614,048 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 17/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T278M) has been classified as Benign.

Frequency

Genomes: 𝑓 0.000039 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000096 ( 0 hom. )

Consequence

SLC52A3
NM_033409.4 missense

Scores

19

Clinical Significance

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

Conservation

PhyloP100: 1.57

Publications

24 publications found
Variant links:
Genes affected
SLC52A3 (HGNC:16187): (solute carrier family 52 member 3) This gene encodes a riboflavin transporter protein that is strongly expressed in the intestine and likely plays a role in intestinal absorption of riboflavin. The protein is predicted to have eleven transmembrane domains and a cell surface localization signal in the C-terminus. Mutations at this locus have been associated with Brown-Vialetto-Van Laere syndrome and Fazio-Londe disease. [provided by RefSeq, Mar 2012]
SLC52A3 Gene-Disease associations (from GenCC):
  • Brown-Vialetto-van Laere syndrome 1
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, G2P, ClinGen, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), PanelApp Australia
  • progressive bulbar palsy
    Inheritance: AR Classification: MODERATE Submitted by: Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -5 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.054332018).
BS1
Variant frequency is greater than expected in population afr. GnomAdExome4 allele frequency = 0.00000958 (14/1461862) while in subpopulation AFR AF = 0.000358 (12/33480). AF 95% confidence interval is 0.000206. There are 0 homozygotes in GnomAdExome4. There are 4 alleles in the male GnomAdExome4 subpopulation. Median coverage is 35. This position passed quality control check. Existence of Clinvar submissions makes me limit the strength of this signal to Supporting

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SLC52A3NM_033409.4 linkc.833C>G p.Thr278Arg missense_variant Exon 3 of 5 ENST00000645534.1 NP_212134.3 Q9NQ40-1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SLC52A3ENST00000645534.1 linkc.833C>G p.Thr278Arg missense_variant Exon 3 of 5 NM_033409.4 ENSP00000494193.1 Q9NQ40-1

Frequencies

GnomAD3 genomes
AF:
0.0000394
AC:
6
AN:
152186
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.000145
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000119
AC:
3
AN:
251306
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.000123
Gnomad AMR exome
AF:
0.00
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:
0.000163
GnomAD4 exome
AF:
0.00000958
AC:
14
AN:
1461862
Hom.:
0
Cov.:
35
AF XY:
0.00000550
AC XY:
4
AN XY:
727238
show subpopulations
African (AFR)
AF:
0.000358
AC:
12
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:
0.00
AC:
0
AN:
39696
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53406
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
1111998
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.486
Heterozygous variant carriers
0
1
3
4
6
7
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:
0.0000394
AC:
6
AN:
152186
Hom.:
0
Cov.:
33
AF XY:
0.0000404
AC XY:
3
AN XY:
74340
show subpopulations
African (AFR)
AF:
0.000145
AC:
6
AN:
41442
American (AMR)
AF:
0.00
AC:
0
AN:
15284
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4834
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68018
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
1
1
2
2
3
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:
0.00
Hom.:
1734
ExAC
AF:
0.0000165
AC:
2

ClinVar

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

Submissions by phenotype

Inborn genetic diseases Uncertain:1
Aug 04, 2020
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.T278R variant (also known as c.833C>G), located in coding exon 2 of the SLC52A3 gene, results from a C to G substitution at nucleotide position 833. The threonine at codon 278 is replaced by arginine, an amino acid with similar properties. This amino acid position is poorly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Brown-Vialetto-van Laere syndrome 1 Uncertain:1
Oct 25, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt SLC52A3 protein function. ClinVar contains an entry for this variant (Variation ID: 839471). This variant has not been reported in the literature in individuals affected with SLC52A3-related conditions. This variant is present in population databases (rs3746803, gnomAD 0.01%). This sequence change replaces threonine, which is neutral and polar, with arginine, which is basic and polar, at codon 278 of the SLC52A3 protein (p.Thr278Arg). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.066
BayesDel_addAF
Benign
-0.35
T
BayesDel_noAF
Benign
-0.50
CADD
Benign
4.3
DANN
Benign
0.27
DEOGEN2
Benign
0.0031
T;T;.;T;T
Eigen
Benign
-1.1
Eigen_PC
Benign
-1.1
FATHMM_MKL
Benign
0.34
N
LIST_S2
Benign
0.39
.;.;T;.;T
M_CAP
Benign
0.034
D
MetaRNN
Benign
0.054
T;T;T;T;T
MetaSVM
Benign
-0.96
T
MutationAssessor
Benign
0.55
N;N;N;N;N
PhyloP100
1.6
PrimateAI
Benign
0.25
T
PROVEAN
Benign
0.42
.;.;N;N;.
REVEL
Benign
0.058
Sift
Benign
0.58
.;.;T;T;.
Sift4G
Benign
0.54
.;T;T;T;.
Polyphen
0.0
B;B;B;B;B
Vest4
0.095, 0.12, 0.092
MutPred
0.20
Loss of glycosylation at T278 (P = 0.025);Loss of glycosylation at T278 (P = 0.025);Loss of glycosylation at T278 (P = 0.025);Loss of glycosylation at T278 (P = 0.025);Loss of glycosylation at T278 (P = 0.025);
MVP
0.31
MPC
0.35
ClinPred
0.0060
T
GERP RS
2.4
Varity_R
0.041
gMVP
0.25
Mutation Taster
=99/1
polymorphism

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

Other links and lift over

dbSNP: rs3746803; hg19: chr20-744382; API