2-227685582-T-G

Variant summary

Our verdict is Benign. Variant got -14 ACMG points: 0P and 14B. BP4_Strong BP6_Moderate BA1

The NM_025243.4(SLC19A3):c.*1815A>C variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.377 in 151,982 control chromosomes in the GnomAD database, including 11,628 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★).

• Frequency:
  • Genomes: 𝑓 0.38 (11628 hom., cov: 32)
  • Exomes 𝑓: 0.13 (0 hom.)
• Consequence: SLC19A3 NM_025243.4 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:2
• Conservation: PhyloP100: 0.214

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]

ACMG classification

Verdict is Benign. Variant got -14 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.89).
• BP6: Variant 2-227685582-T-G is Benign according to our data. Variant chr2-227685582-T-G is described in ClinVar as [Benign]. Clinvar id is 334844.Status of the report is criteria_provided_single_submitter, 1 stars.
• BA1: GnomAd4 highest subpopulation (NFE) allele frequency at 95% confidence interval = 0.456 is higher than 0.05.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
SLC19A3	NM_025243.4	c.*1815A>C		3_prime_UTR_variant	6/6	ENST00000644224.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC19A3	ENST00000644224.2	c.*1815A>C		3_prime_UTR_variant	6/6		NM_025243.4	P1
SLC19A3	ENST00000647113.1	c.*2294A>C		3_prime_UTR_variant, NMD_transcript_variant	4/4

Frequencies

GnomAD3 genomes AF: 0.377 AC: 57201 AN: 151856 Hom.: 11620 Cov.: 32

Gnomad AFR AF: 0.310

Gnomad AMI AF: 0.409

Gnomad AMR AF: 0.303

Gnomad ASJ AF: 0.384

Gnomad EAS AF: 0.00406

Gnomad SAS AF: 0.249

Gnomad FIN AF: 0.443

Gnomad MID AF: 0.427

Gnomad NFE AF: 0.460

Gnomad OTH AF: 0.378

GnomAD4 exome AF: 0.125 AC: 1 AN: 8 Hom.: 0 Cov.: 0 AF XY: 0.167 AC XY: 1 AN XY: 6

Gnomad4 NFE exome AF: 0.125

GnomAD4 genome AF: 0.377 AC: 57231 AN: 151974 Hom.: 11628 Cov.: 32 AF XY: 0.373 AC XY: 27671 AN XY: 74258

Gnomad4 AFR AF: 0.310

Gnomad4 AMR AF: 0.303

Gnomad4 ASJ AF: 0.384

Gnomad4 EAS AF: 0.00407

Gnomad4 SAS AF: 0.250

Gnomad4 FIN AF: 0.443

Gnomad4 NFE AF: 0.460

Gnomad4 OTH AF: 0.374

Alfa AF: 0.269 Hom.: 679

Bravo AF: 0.360

Asia WGS AF: 0.126 AC: 441 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:2

Revision: criteria provided, single submitter

Submissions by phenotype

Biotin-responsive basal ganglia disease Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jan 13, 2018

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. -

Thiamine Metabolism Dysfunction Syndrome Benign:1

Benign, criteria provided, single submitter

clinical testing

Illumina Laboratory Services, Illumina

Jun 14, 2016

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.89
Cadd	Benign	2.3
Dann	Benign	0.67

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs34020562; hg19: chr2-228550298;