NM_033409.4:c.203G>C

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -3 ACMG points: 0P and 3B. BP4_ModerateBS1_Supporting

The NM_033409.4(SLC52A3):c.203G>C(p.Cys68Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000215 in 1,582,136 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 (★★).

Frequency

Genomes: 𝑓 0.00014 ( 0 hom., cov: 31)

Exomes 𝑓: 0.00022 ( 0 hom. )

Consequence

SLC52A3
NM_033409.4 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 0.280

Publications

2 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

SLC52A3 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -3 ACMG points.

BP4

Computational evidence support a benign effect (MetaRNN=0.12685952).

BS1

Variant frequency is greater than expected in population nfe. GnomAd4 allele frequency = 0.000145 (22/152122) while in subpopulation NFE AF = 0.000294 (20/68022). AF 95% confidence interval is 0.000194. There are 0 homozygotes in GnomAd4. There are 6 alleles in the male GnomAd4 subpopulation. Median coverage is 31. 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
SLC52A3	NM_033409.4 link	c.203G>C	p.Cys68Ser	missense_variant	Exon 2 of 5	ENST00000645534.1	NP_212134.3	Q9NQ40-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC52A3	ENST00000645534.1 link	c.203G>C	p.Cys68Ser	missense_variant	Exon 2 of 5		NM_033409.4	ENSP00000494193.1		Q9NQ40-1

Frequencies

GnomAD3 genomes

AF:

0.000145

AC:

AN:

152122

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

Gnomad ASJ

AF:

0.000288

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000810

AC:

AN:

197594

AF XY:

0.0000855

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.0000572

Gnomad NFE exome

AF:

0.000163

Gnomad OTH exome

AF:

0.000196

GnomAD4 exome

AF:

0.000222

AC:

318

AN:

1430014

Hom.:

Cov.:

AF XY:

0.000225

AC XY:

159

AN XY:

708040

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33056

American (AMR)

AF:

0.00

AC:

AN:

38490

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25388

East Asian (EAS)

AF:

0.00

AC:

AN:

38390

South Asian (SAS)

AF:

0.00

AC:

AN:

81834

European-Finnish (FIN)

AF:

0.0000195

AC:

AN:

51374

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5724

European-Non Finnish (NFE)

AF:

0.000284

AC:

311

AN:

1096444

Other (OTH)

AF:

0.000101

AC:

AN:

59314

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.483

Heterozygous variant carriers

101

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

100

<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:

0.000145

AC:

AN:

152122

Hom.:

Cov.:

AF XY:

0.0000808

AC XY:

AN XY:

74290

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41412

American (AMR)

AF:

0.0000655

AC:

AN:

15268

Ashkenazi Jewish (ASJ)

AF:

0.000288

AC:

AN:

3470

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.000294

AC:

AN:

68022

Other (OTH)

AF:

0.00

AC:

AN:

2092

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.530

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:

0.000155

Hom.:

Bravo

AF:

0.0000907

TwinsUK

AF:

0.00

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.0000331

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Apr 30, 2025

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

In silico analysis indicates that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Breakthrough Genomics, Breakthrough Genomics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:not provided

- -

Inborn genetic diseases

Uncertain:1

Jun 01, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.C68S variant (also known as c.203G>C), located in coding exon 1 of the SLC52A3 gene, results from a G to C substitution at nucleotide position 203. The cysteine at codon 68 is replaced by serine, an amino acid with dissimilar properties. This amino acid position is not well 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

Dec 18, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces cysteine, which is neutral and slightly polar, with serine, which is neutral and polar, at codon 68 of the SLC52A3 protein (p.Cys68Ser). This variant is present in population databases (rs149622425, gnomAD 0.02%). 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: 452583). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on SLC52A3 protein function. 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

0.11

BayesDel_addAF

Benign

-0.18

BayesDel_noAF

Benign

-0.23

CADD

Benign

(source)

DANN

Benign

0.82

DEOGEN2

Benign

0.0033

T;T;.;T;T

Eigen

Benign

-0.27

Eigen_PC

Benign

-0.10

FATHMM_MKL

Benign

0.76

LIST_S2

Benign

0.56

.;.;T;.;T

M_CAP

Benign

0.018

MetaRNN

Benign

0.13

T;T;T;T;T

MetaSVM

Benign

-0.42

MutationAssessor

Benign

1.6

L;L;L;L;L

PhyloP100

0.28

PrimateAI

Benign

0.31

PROVEAN

Benign

-0.63

.;.;N;N;.

REVEL

Benign

0.28

Sift

Benign

0.41

.;.;T;T;.

Sift4G

Benign

0.42

.;T;T;T;.

Polyphen

0.050

B;B;B;B;B

Vest4

0.10, 0.10

MutPred

0.39

Gain of disorder (P = 1e-04);Gain of disorder (P = 1e-04);Gain of disorder (P = 1e-04);Gain of disorder (P = 1e-04);Gain of disorder (P = 1e-04);

MVP

0.69

MPC

0.39

ClinPred

0.032

GERP RS

4.8

PromoterAI

-0.015

Neutral

(source)

Varity_R

0.090

gMVP

0.46

Mutation Taster

=94/6

polymorphism

(source)

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

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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