2-227685423-C-A

Variant names:

• chr2-227685423-C-A
• rs1134282
• NM_025243.4:c.*1974G>T

Variant summary

Our verdict is Benign. The variant received -20 ACMG points: 0P and 20B. BP4_Strong BP6_Very_Strong BA1

The NM_025243.4(SLC19A3):​c.*1974G>T variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0739 in 152,146 control chromosomes in the GnomAD database, including 1,169 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

• Frequency:
  • Genomes: 𝑓 0.074 (1169 hom., cov: 32)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: SLC19A3 NM_025243.4 3_prime_UTR
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:2
• Conservation: PhyloP100: -0.843
• Publications: 0 publications found

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

ACMG classification

Our verdict: Benign. The variant received -20 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-1.01).
• BP6: Variant 2-227685423-C-A is Benign according to our data. Variant chr2-227685423-C-A is described in ClinVar as [Benign]. Clinvar id is 334838.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BA1: GnomAd4 highest subpopulation (AFR) allele frequency at 95% confidence interval = 0.233 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
SLC19A3	NM_025243.4	c.*1974G>T		3_prime_UTR_variant	Exon 6 of 6	ENST00000644224.2	NP_079519.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
SLC19A3	ENST00000644224.2	c.*1974G>T		3_prime_UTR_variant	Exon 6 of 6		NM_025243.4	ENSP00000495385.1
SLC19A3	ENST00000647113.1	n.*2453G>T		non_coding_transcript_exon_variant	Exon 4 of 4			ENSP00000494966.1
SLC19A3	ENST00000647113.1	n.*2453G>T		3_prime_UTR_variant	Exon 4 of 4			ENSP00000494966.1

Frequencies

GnomAD3 genomes AF: 0.0737 AC: 11204 AN: 152028 Hom.: 1167 Cov.: 32

Gnomad AFR AF: 0.237

Gnomad AMI AF: 0.00110

Gnomad AMR AF: 0.0311

Gnomad ASJ AF: 0.00691

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00455

Gnomad FIN AF: 0.000283

Gnomad MID AF: 0.0285

Gnomad NFE AF: 0.0111

Gnomad OTH AF: 0.0569

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 62 Hom.: 0 Cov.: 0 AF XY: 0.00 AC XY: 0 AN XY: 42

African (AFR) AC: 0 AN: 0

American (AMR) AC: 0 AN: 0

Ashkenazi Jewish (ASJ) AC: 0 AN: 0

East Asian (EAS) AF: 0.00 AC: 0 AN: 2

South Asian (SAS) AF: 0.00 AC: 0 AN: 2

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 2

Middle Eastern (MID) AC: 0 AN: 0

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 54

Other (OTH) AF: 0.00 AC: 0 AN: 2

GnomAD4 genome AF: 0.0739 AC: 11236 AN: 152146 Hom.: 1169 Cov.: 32 AF XY: 0.0718 AC XY: 5345 AN XY: 74396

African (AFR) AF: 0.237 AC: 9829 AN: 41450

American (AMR) AF: 0.0310 AC: 474 AN: 15274

Ashkenazi Jewish (ASJ) AF: 0.00691 AC: 24 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5178

South Asian (SAS) AF: 0.00435 AC: 21 AN: 4826

European-Finnish (FIN) AF: 0.000283 AC: 3 AN: 10612

Middle Eastern (MID) AF: 0.0272 AC: 8 AN: 294

European-Non Finnish (NFE) AF: 0.0111 AC: 755 AN: 68014

Other (OTH) AF: 0.0572 AC: 121 AN: 2114

Alfa AF: 0.0474 Hom.: 71

Bravo AF: 0.0832

Asia WGS AF: 0.0180 AC: 64 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Biotin-responsive basal ganglia disease Benign:1

Jan 13, 2018

Illumina Laboratory Services, Illumina

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -

not provided Benign:1

-

Breakthrough Genomics, Breakthrough Genomics

Significance: Benign

Review Status: criteria provided, single submitter

Collection Method: not provided

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-1.0
CADD	Benign	1.5
DANN	Benign	0.63
PhyloP100		-0.84

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1134282; hg19: chr2-228550139;