rs587783008

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP5

The NM_001370658.1(BTD):c.250-15del variant causes a splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000384 in 1,563,456 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000035 ( 0 hom. )

Consequence

BTD
NM_001370658.1 splice_polypyrimidine_tract, intron

Scores

Not classified

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:5U:1

Conservation

PhyloP100: 0.977

Variant links:

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]

BTD links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 3 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 3-15641892-AT-A is Pathogenic according to our data. Variant chr3-15641892-AT-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 156006.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1, Pathogenic=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BTD	NM_001370658.1 linkuse as main transcript	c.250-15del		splice_polypyrimidine_tract_variant, intron_variant		ENST00000643237.3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BTD	ENST00000643237.3 linkuse as main transcript	c.250-15del		splice_polypyrimidine_tract_variant, intron_variant			NM_001370658.1	P1	P43251-4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152232

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000828

AC:

AN:

241528

Hom.:

AF XY:

0.00000767

AC XY:

AN XY:

130346

show subpopulations

Gnomad AFR exome

AF:

0.000129

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000354

AC:

AN:

1411224

Hom.:

Cov.:

AF XY:

0.00000284

AC XY:

AN XY:

704266

show subpopulations

Gnomad4 AFR exome

AF:

0.000154

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152232

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74390

show subpopulations

Gnomad4 AFR

AF:

0.0000241

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:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000453

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:5Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Biotinidase deficiency

Pathogenic:5Uncertain:1

Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	May 25, 2023	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 13, 2023	Variant summary: BTD c.250-15delT, also referred to as c.310-15delT, alters a nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Several computational tools predict a significant impact on normal splicing: One predicts the variant creates a 3' acceptor site, two predict the variant weakens a canonical 3' acceptor site, and one predicts the variant has no significant impact on splicing. However, a functional study found no evidence that the variant impacts splicing (Li_2014). The variant allele was found at a frequency of 8.3e-06 in 241528 control chromosomes (gnomAD). c.250-15delT has been reported in the literature in the compound heterozygous state in individuals affected with partial Biotinidase Deficiency, including at least one case where it was confirmed to be in trans with a pathogenic variant (e.g. Li_2014, Procter_2016, Carvalho_2019, Carvalho_2020). These data indicate that the variant may be associated with disease. Experimental evidence evaluating an impact of the variant found that although it does not appear to impact splicing, the variant may result in decreased mRNA expression (Li_2014). This study found that a patient who was compound heterozygous for the variant and the patient's mother, who was a heterozygous carrier, both exhibited decreased mRNA expression, approximately 40% and 65%, respectively, compared to control individuals. Three ClinVar submitters (evaluation after 2014) cite this variant as uncertain significance, likely pathogenic and pathogenic. Based on the evidence outlined above, the variant was classified as likely pathogenic. -
Likely pathogenic, criteria provided, single submitter	clinical testing	Mendelics	May 28, 2019	- -
Pathogenic, no assertion criteria provided	clinical testing	Molecular Genetics Diagnostic Laboratory, Detroit Medical Center University Laboratories	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 22, 2024	This sequence change falls in intron 2 of the BTD gene. It does not directly change the encoded amino acid sequence of the BTD protein. It affects a nucleotide within the consensus splice site. This variant is present in population databases (rs587783008, gnomAD 0.01%). This variant has been observed in individual(s) with biotinidase deficiency (PMID: 24797656, 26810761, 30912303). 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: 156006). Studies have shown that this variant alters BTD gene expression (PMID: 24797656). Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	May 29, 2018	- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.27

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.24

Position offset: 3

DS_AL_spliceai

0.27

Position offset: 16

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over