2-227685558-C-T

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.*1839G>A variant causes a 3 prime UTR change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0738 in 152,178 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: 0.038 (0 hom.)
• Consequence: SLC19A3 NM_025243.4 3_prime_UTR
• Clinical Significance: Benign criteria provided, single submitter B:1
• Conservation: PhyloP100: 0.212

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=-0.79).
• BP6: Variant 2-227685558-C-T is Benign according to our data. Variant chr2-227685558-C-T is described in ClinVar as [Benign]. Clinvar id is 334842.Status of the report is criteria_provided_single_submitter, 1 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/exons	MANE	UniProt
SLC19A3	NM_025243.4	c.*1839G>A		3_prime_UTR_variant	6/6	ENST00000644224.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
SLC19A3	ENST00000644224.2	c.*1839G>A		3_prime_UTR_variant	6/6		NM_025243.4	P1
SLC19A3	ENST00000647113.1	c.*2318G>A		3_prime_UTR_variant, NMD_transcript_variant	4/4

Frequencies

GnomAD3 genomes AF: 0.0737 AC: 11201 AN: 152008 Hom.: 1167 Cov.: 32

Gnomad AFR AF: 0.237

Gnomad AMI AF: 0.00110

Gnomad AMR AF: 0.0310

Gnomad ASJ AF: 0.00692

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00456

Gnomad FIN AF: 0.000283

Gnomad MID AF: 0.0285

Gnomad NFE AF: 0.0111

Gnomad OTH AF: 0.0566

GnomAD4 exome AF: 0.0385 AC: 2 AN: 52 Hom.: 0 Cov.: 0 AF XY: 0.0588 AC XY: 2 AN XY: 34

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.0526

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0738 AC: 11232 AN: 152126 Hom.: 1169 Cov.: 32 AF XY: 0.0718 AC XY: 5343 AN XY: 74380

Gnomad4 AFR AF: 0.237

Gnomad4 AMR AF: 0.0310

Gnomad4 ASJ AF: 0.00692

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00436

Gnomad4 FIN AF: 0.000283

Gnomad4 NFE AF: 0.0111

Gnomad4 OTH AF: 0.0570

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:1

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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.79
Cadd	Benign	3.4
Dann	Benign	0.86

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs74372767; hg19: chr2-228550274;