chr20-761073-G-A

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 4P and 1B. PM1PM2BP4

The NM_033409.4(SLC52A3):​c.1363C>T​(p.Arg455Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000087 in 1,609,764 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 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: 0.0000069 ( 0 hom. )

Consequence

SLC52A3
NM_033409.4 missense

Scores

3
16

Clinical Significance

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

Conservation

PhyloP100: -1.76

Publications

1 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: Uncertain_significance. The variant received 3 ACMG points.

PM1
In a mutagenesis_site No effect on cell surface localization. (size 0) in uniprot entity S52A3_HUMAN
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.2794183).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SLC52A3NM_033409.4 linkc.1363C>T p.Arg455Trp missense_variant Exon 5 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.1363C>T p.Arg455Trp missense_variant Exon 5 of 5 NM_033409.4 ENSP00000494193.1 Q9NQ40-1

Frequencies

GnomAD3 genomes
AF:
0.0000263
AC:
4
AN:
152230
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000241
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:
0.0000441
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000844
AC:
2
AN:
236998
AF XY:
0.00000770
show subpopulations
Gnomad AFR exome
AF:
0.0000710
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:
0.00000942
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000686
AC:
10
AN:
1457534
Hom.:
0
Cov.:
30
AF XY:
0.00000552
AC XY:
4
AN XY:
724878
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33384
American (AMR)
AF:
0.00
AC:
0
AN:
44462
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26082
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39464
South Asian (SAS)
AF:
0.00
AC:
0
AN:
85646
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
51878
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5728
European-Non Finnish (NFE)
AF:
0.00000900
AC:
10
AN:
1110700
Other (OTH)
AF:
0.00
AC:
0
AN:
60190
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.495
Heterozygous variant carriers
0
1
2
4
5
6
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:
152230
Hom.:
0
Cov.:
32
AF XY:
0.0000403
AC XY:
3
AN XY:
74368
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41468
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:
5192
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4838
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10618
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
314
European-Non Finnish (NFE)
AF:
0.0000441
AC:
3
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.475
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:
0.0000579
Hom.:
0
Bravo
AF:
0.0000151

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
Mar 18, 2025
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.1363C>T (p.R455W) alteration is located in exon 5 (coding exon 4) of the SLC52A3 gene. This alteration results from a C to T substitution at nucleotide position 1363, causing the arginine (R) at amino acid position 455 to be replaced by a tryptophan (W). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Brown-Vialetto-van Laere syndrome 1 Uncertain:1
Jul 19, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 455 of the SLC52A3 protein (p.Arg455Trp). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with SLC52A3-related conditions. ClinVar contains an entry for this variant (Variation ID: 476602). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.13
BayesDel_addAF
Benign
-0.041
T
BayesDel_noAF
Benign
-0.30
CADD
Benign
17
DANN
Uncertain
1.0
DEOGEN2
Benign
0.021
T;T;T;T
Eigen
Benign
-0.70
Eigen_PC
Benign
-0.95
FATHMM_MKL
Benign
0.14
N
LIST_S2
Benign
0.71
.;.;.;T
M_CAP
Benign
0.062
D
MetaRNN
Benign
0.28
T;T;T;T
MetaSVM
Benign
-0.49
T
MutationAssessor
Uncertain
2.4
M;M;M;M
PhyloP100
-1.8
PrimateAI
Benign
0.29
T
PROVEAN
Benign
-1.6
.;.;N;.
REVEL
Uncertain
0.39
Sift
Benign
0.092
.;.;T;.
Sift4G
Benign
0.16
.;T;T;.
Polyphen
1.0
D;D;D;D
Vest4
0.26, 0.26
MVP
0.51
MPC
0.71
ClinPred
0.60
D
GERP RS
-7.3
Varity_R
0.058
gMVP
0.43
Mutation Taster
=91/9
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: rs939576852; hg19: chr20-741717; API