2-227699221-G-T

Variant names:

Variant summary

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

The NM_025243.4(SLC19A3):c.494C>A(p.Ala165Glu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000112 in 1,613,958 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. A165P) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000033 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

SLC19A3
NM_025243.4 missense

Scores

Clinical Significance

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

Conservation

PhyloP100: 2.35

Publications

4 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

SLC19A3 links:

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, 11 uncertain in NM_025243.4

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.23757505).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC19A3	NM_025243.4 link	c.494C>A	p.Ala165Glu	missense_variant	Exon 3 of 6	ENST00000644224.2	NP_079519.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC19A3	ENST00000644224.2 link	c.494C>A	p.Ala165Glu	missense_variant	Exon 3 of 6		NM_025243.4	ENSP00000495385.1

Frequencies

GnomAD3 genomes

AF:

0.0000329

AC:

AN:

152124

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000724

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000385

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:

AN:

251420

AF XY:

0.0000221

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000163

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000889

AC:

AN:

1461834

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

727214

show subpopulations

African (AFR)

AF:

0.0000299

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.000126

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53386

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1111986

Other (OTH)

AF:

0.000116

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.463

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome 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

GnomAD4 genome

AF:

0.0000329

AC:

AN:

152124

Hom.:

Cov.:

AF XY:

0.0000404

AC XY:

AN XY:

74316

show subpopulations

African (AFR)

AF:

0.0000724

AC:

AN:

41450

American (AMR)

AF:

0.00

AC:

AN:

15250

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3470

East Asian (EAS)

AF:

0.000385

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10606

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68026

Other (OTH)

AF:

0.00

AC:

AN:

2080

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.495

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:

0.0000329

Hom.:

Bravo

AF:

0.0000642

ESP6500AA

AF:

0.000454

AC:

ESP6500EA

AF:

0.00

AC:

ExAC

AF:

0.00000824

AC:

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 15, 2022

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The c.494C>A (p.A165E) alteration is located in exon 3 (coding exon 2) of the SLC19A3 gene. This alteration results from a C to A substitution at nucleotide position 494, causing the alanine (A) at amino acid position 165 to be replaced by a glutamic acid (E). Based on data from gnomAD, the A allele has an overall frequency of <0.01% (5/282824) total alleles studied. The highest observed frequency was 0.02% (4/19952) of East Asian alleles. This amino acid position is not well conserved in available vertebrate species. This alteration is predicted to be tolerated by in silico analysis. Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Biotin-responsive basal ganglia disease

Uncertain:1

Aug 16, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with glutamic acid, which is acidic and polar, at codon 165 of the SLC19A3 protein (p.Ala165Glu). This variant is present in population databases (rs144223086, gnomAD 0.02%). 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: 574758). 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 SLC19A3 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

0.23

BayesDel_addAF

Benign

-0.14

BayesDel_noAF

Benign

-0.17

CADD

Benign

(source)

DANN

Uncertain

0.98

DEOGEN2

Uncertain

0.53

D;D;.;.

Eigen

Benign

-0.55

Eigen_PC

Benign

-0.60

FATHMM_MKL

Benign

0.71

LIST_S2

Uncertain

0.91

.;D;D;T

M_CAP

Benign

0.053

MetaRNN

Benign

0.24

T;T;T;T

MetaSVM

Benign

-0.30

MutationAssessor

Benign

2.0

M;M;.;.

PhyloP100

2.4

PrimateAI

Uncertain

0.50

PROVEAN

Uncertain

-2.8

.;D;.;.

REVEL

Uncertain

0.34

Sift

Benign

0.084

.;T;.;.

Sift4G

Benign

0.34

.;T;.;.

Polyphen

0.93

P;P;.;.

Vest4

0.31

MVP

0.73

MPC

0.20

ClinPred

0.20

GERP RS

2.9

Varity_R

0.15

gMVP

0.27

Mutation Taster

=72/28

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