rs764398318

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_025243.4(SLC19A3):​c.151A>G​(p.Ile51Val) variant causes a missense, splice region change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000167 in 1,613,846 control chromosomes in the GnomAD database, including 1 homozygotes. In-silico tool predicts a benign outcome for this variant. 19/24 in silico tools predict a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. I51M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.000018 ( 1 hom. )

Consequence

SLC19A3
NM_025243.4 missense, splice_region

Scores

19
Splicing: ADA: 0.00002445
2

Clinical Significance

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

Conservation

PhyloP100: 1.03

Publications

1 publications found
Variant links:
Genes affected
SLC19A3 (HGNC:16266): (solute carrier family 19 member 3) This gene encodes a ubiquitously expressed transmembrane thiamine transporter that lacks folate transport activity. Mutations in this gene cause biotin-responsive basal ganglia disease (BBGD); a recessive disorder manifested in childhood that progresses to chronic encephalopathy, dystonia, quadriparesis, and death if untreated. Patients with BBGD have bilateral necrosis in the head of the caudate nucleus and in the putamen. Administration of high doses of biotin in the early progression of the disorder eliminates pathological symptoms while delayed treatment results in residual paraparesis, mild cognitive disability, or dystonia. Administration of thiamine is ineffective in the treatment of this disorder. Experiments have failed to show that this protein can transport biotin. Mutations in this gene also cause a Wernicke's-like encephalopathy.[provided by RefSeq, Jan 2010]
SLC19A3 Gene-Disease associations (from GenCC):
  • biotin-responsive basal ganglia disease
    Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Genomics England PanelApp, G2P
  • Leigh syndrome
    Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen
  • infantile spams-psychomotor retardation-progressive brain atrophy-basal ganglia disease syndrome
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • Leigh syndrome with leukodystrophy
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • thiamine-responsive encephalopathy
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

PM1
In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 8 uncertain in NM_025243.4
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.08407694).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SLC19A3NM_025243.4 linkc.151A>G p.Ile51Val missense_variant, splice_region_variant Exon 3 of 6 ENST00000644224.2 NP_079519.1 Q9BZV2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SLC19A3ENST00000644224.2 linkc.151A>G p.Ile51Val missense_variant, splice_region_variant Exon 3 of 6 NM_025243.4 ENSP00000495385.1 Q9BZV2

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
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:
0.00
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000321
AC:
8
AN:
249576
AF XY:
0.0000444
show subpopulations
Gnomad AFR exome
AF:
0.0000616
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:
0.0000536
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000178
AC:
26
AN:
1461616
Hom.:
1
Cov.:
32
AF XY:
0.0000261
AC XY:
19
AN XY:
727138
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33476
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000927
AC:
8
AN:
86254
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53342
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000126
AC:
14
AN:
1111838
Other (OTH)
AF:
0.0000662
AC:
4
AN:
60380
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.487
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:
0.00000657
AC:
1
AN:
152230
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74364
show subpopulations
African (AFR)
AF:
0.0000241
AC:
1
AN:
41462
American (AMR)
AF:
0.00
AC:
0
AN:
15272
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
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:
10624
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.00
AC:
0
AN:
68042
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.0000777
Hom.:
0
Bravo
AF:
0.0000302
ExAC
AF:
0.0000330
AC:
4
EpiCase
AF:
0.000218
EpiControl
AF:
0.000237

ClinVar

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

Submissions by phenotype

Biotin-responsive basal ganglia disease Uncertain:1
Aug 22, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 51 of the SLC19A3 protein (p.Ile51Val). This variant is present in population databases (rs764398318, gnomAD 0.007%). This variant has not been reported in the literature in individuals affected with SLC19A3-related conditions. ClinVar contains an entry for this variant (Variation ID: 533545). Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The valine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -

not provided Uncertain:1
Jul 18, 2025
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis suggests that this missense variant does not alter protein structure/function; Has not been previously published as pathogenic or benign to our knowledge; This variant is associated with the following publications: (PMID: 26657515) -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.094
BayesDel_addAF
Benign
-0.20
T
BayesDel_noAF
Benign
-0.34
CADD
Benign
0.40
DANN
Benign
0.28
DEOGEN2
Benign
0.13
T;.;T;.;.;.;.
Eigen
Benign
-1.1
Eigen_PC
Benign
-0.93
FATHMM_MKL
Benign
0.70
D
LIST_S2
Benign
0.63
.;T;T;T;T;T;T
M_CAP
Benign
0.037
D
MetaRNN
Benign
0.084
T;T;T;T;T;T;T
MetaSVM
Benign
-0.82
T
MutationAssessor
Benign
0.50
N;.;N;.;.;.;.
PhyloP100
1.0
PrimateAI
Benign
0.38
T
PROVEAN
Benign
0.50
.;N;N;.;.;N;N
REVEL
Benign
0.17
Sift
Benign
1.0
.;T;T;.;.;T;T
Sift4G
Benign
1.0
.;T;T;.;.;.;T
Polyphen
0.0010
B;.;B;.;.;.;.
Vest4
0.085, 0.017
MutPred
0.40
Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);.;.;Gain of sheet (P = 0.1208);Gain of sheet (P = 0.1208);
MVP
0.33
MPC
0.051
ClinPred
0.018
T
GERP RS
-1.2
Varity_R
0.021
gMVP
0.20
Mutation Taster
=73/27
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.000024
dbscSNV1_RF
Benign
0.0040
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: rs764398318; hg19: chr2-228564280; API