rs397514373

chr3-15644447-TGTC-T

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PM1 PM2 PM4_Supporting PP3 PP5_Very_Strong

The NM_001370658.1(BTD):c.534_536del(p.Val179del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,614,010 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Likely pathogenic (★★). Synonymous variant affecting the same amino acid position (i.e. V178V) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: BTD NM_001370658.1 inframe_deletion
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 8.14

Genes affected

BTD (HGNC:1122): (biotinidase) The protein encoded by this gene functions to recycle protein-bound biotin by cleaving biocytin (biotin-epsilon-lysine), a normal product of carboxylase degradation, resulting in regeneration of free biotin. The encoded protein has also been shown to have biotinyl transferase activity. Mutations in this gene are associated with biotinidase deficiency. Multiple transcript variants encoding different isoforms have been described. [provided by RefSeq, Aug 2013]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 3 uncertain in NM_001370658.1
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_001370658.1. Strenght limited to Supporting due to length of the change: 1aa.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP
• PP5: Variant 3-15644447-TGTC-T is Pathogenic according to our data. Variant chr3-15644447-TGTC-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 587749.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-15644447-TGTC-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BTD	NM_001370658.1	c.534_536del	p.Val179del	inframe_deletion	4/4	ENST00000643237.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BTD	ENST00000643237.3	c.534_536del	p.Val179del	inframe_deletion	4/4		NM_001370658.1	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152118 Hom.: 0 Cov.: 31

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1461892 Hom.: 0 AF XY: 0.00000138 AC XY: 1 AN XY: 727246

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152118 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74294

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Biotinidase deficiency Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 17, 2023

This variant, c.594_596del, results in the deletion of 1 amino acid(s) of the BTD protein (p.Val199del), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individual(s) with biotinidase deficiency (PMID: 9396567, 25174816). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 587749). This variant disrupts the p.Val199 amino acid residue in BTD. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 12359137, 15060693, 25174816, 28498829). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

Sep 20, 2018

Not found in the total gnomAD dataset, and the data is high quality (0/277192 chr). Found in at least one symptomatic patient. Assessment of experimental evidence suggests this variant results in abnormal protein function. -

Computational scores

Source: dbNSFP v4.3

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

LitVar

Other links and lift over

dbSNP: rs397514373; hg19: chr3-15685954;