2-227702301-A-T

Variant summary

Our verdict is Benign. The variant received -21 ACMG points: 0P and 21B. BP4_StrongBP6_Very_StrongBP7BS1BS2

The NM_025243.4(SLC19A3):​c.18T>A​(p.Thr6Thr) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000639 in 1,614,158 control chromosomes in the GnomAD database, including 14 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. T6T) has been classified as Likely benign.

Frequency

Genomes: 𝑓 0.00079 ( 1 hom., cov: 32)
Exomes 𝑓: 0.00062 ( 13 hom. )

Consequence

SLC19A3
NM_025243.4 synonymous

Scores

2

Clinical Significance

Benign/Likely benign criteria provided, multiple submitters, no conflicts B:6

Conservation

PhyloP100: -0.533

Publications

3 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: Benign. The variant received -21 ACMG points.

BP4
Computational evidence support a benign effect (BayesDel_noAF=-0.81).
BP6
Variant 2-227702301-A-T is Benign according to our data. Variant chr2-227702301-A-T is described in ClinVar as Benign/Likely_benign. ClinVar VariationId is 388633.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
BP7
Synonymous conserved (PhyloP=-0.533 with no splicing effect.
BS1
Variant frequency is greater than expected in population eas. GnomAd4 allele frequency = 0.000788 (120/152312) while in subpopulation EAS AF = 0.0195 (101/5188). AF 95% confidence interval is 0.0164. There are 1 homozygotes in GnomAd4. There are 68 alleles in the male GnomAd4 subpopulation. Median coverage is 32. This position passed quality control check.
BS2
High Homozygotes in GnomAdExome4 at 13 AR gene

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
SLC19A3NM_025243.4 linkc.18T>A p.Thr6Thr synonymous_variant Exon 2 of 6 ENST00000644224.2 NP_079519.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
SLC19A3ENST00000644224.2 linkc.18T>A p.Thr6Thr synonymous_variant Exon 2 of 6 NM_025243.4 ENSP00000495385.1

Frequencies

GnomAD3 genomes
AF:
0.000788
AC:
120
AN:
152194
Hom.:
1
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.0000483
Gnomad AMI
AF:
0.00439
Gnomad AMR
AF:
0.000131
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.0194
Gnomad SAS
AF:
0.00186
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000294
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00171
AC:
431
AN:
251364
AF XY:
0.00170
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000289
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0213
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000528
Gnomad OTH exome
AF:
0.000978
GnomAD4 exome
AF:
0.000623
AC:
911
AN:
1461846
Hom.:
13
Cov.:
31
AF XY:
0.000660
AC XY:
480
AN XY:
727218
show subpopulations
African (AFR)
AF:
0.0000299
AC:
1
AN:
33478
American (AMR)
AF:
0.0000447
AC:
2
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26134
East Asian (EAS)
AF:
0.0189
AC:
750
AN:
39692
South Asian (SAS)
AF:
0.00107
AC:
92
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53408
Middle Eastern (MID)
AF:
0.000173
AC:
1
AN:
5768
European-Non Finnish (NFE)
AF:
0.0000189
AC:
21
AN:
1111988
Other (OTH)
AF:
0.000729
AC:
44
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.484
Heterozygous variant carriers
0
49
97
146
194
243
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Exome Hom
Variant carriers
0
20
40
60
80
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:
0.000788
AC:
120
AN:
152312
Hom.:
1
Cov.:
32
AF XY:
0.000913
AC XY:
68
AN XY:
74472
show subpopulations
African (AFR)
AF:
0.0000481
AC:
2
AN:
41556
American (AMR)
AF:
0.000131
AC:
2
AN:
15294
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.0195
AC:
101
AN:
5188
South Asian (SAS)
AF:
0.00187
AC:
9
AN:
4824
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000294
AC:
2
AN:
68040
Other (OTH)
AF:
0.00
AC:
0
AN:
2112
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.483
Heterozygous variant carriers
0
6
13
19
26
32
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Genome Hom
Variant carriers
0
4
8
12
16
20
<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:
0.000299
Hom.:
0
Bravo
AF:
0.00120
Asia WGS
AF:
0.00664
AC:
23
AN:
3478

ClinVar

Significance: Benign/Likely benign
Submissions summary: Benign:6
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Biotin-responsive basal ganglia disease Benign:3
Apr 27, 2017
Illumina Laboratory Services, Illumina
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant was observed as part of a predisposition screen in an ostensibly healthy population. A literature search was performed for the gene, cDNA change, and amino acid change (where applicable). No publications were found based on this search. Allele frequency data from public databases was too high to be consistent with this variant causing disease. Therefore, this variant is classified as benign.

Jan 27, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

May 14, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not provided Benign:2
Apr 13, 2021
GeneDx
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Breakthrough Genomics, Breakthrough Genomics
Significance:Likely benign
Review Status:criteria provided, single submitter
Collection Method:not provided

SLC19A3-related disorder Benign:1
May 05, 2020
PreventionGenetics, part of Exact Sciences
Significance:Benign
Review Status:no assertion criteria provided
Collection Method:clinical testing

This variant is classified as benign based on ACMG/AMP sequence variant interpretation guidelines (Richards et al. 2015 PMID: 25741868, with internal and published modifications).

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
BayesDel_noAF
Benign
-0.81
CADD
Benign
0.26
DANN
Benign
0.67
PhyloP100
-0.53
Mutation Taster
=300/0
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: rs141093593; hg19: chr2-228567017; COSMIC: COSV51453044; COSMIC: COSV51453044; API