rs750598655

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1PM2PP2PP3

The NM_001370658.1(BTD):c.1421A>G(p.Tyr474Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000867 in 1,614,170 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. Y474Y) has been classified as Likely benign.

Frequency

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

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

BTD
NM_001370658.1 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 2.26

Publications

2 publications found

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 Gene-Disease associations (from GenCC):

biotinidase deficiency
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Myriad Women’s Health, ClinGen, Orphanet, Ambry Genetics, G2P, Labcorp Genetics (formerly Invitae)
Leigh syndrome
Inheritance: AR Classification: MODERATE Submitted by: ClinGen

BTD links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

PM1

In a hotspot region, there are 5 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;

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 88 curated pathogenic missense variants (we use a threshold of 10). The gene has 9 curated benign missense variants. Gene score misZ: -0.52516 (below the threshold of 3.09). Trascript score misZ: 0.15371 (below the threshold of 3.09). GenCC associations: The gene is linked to Leigh syndrome, biotinidase deficiency.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.785

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BTD	NM_001370658.1 link	c.1421A>G	p.Tyr474Cys	missense_variant	Exon 4 of 4	ENST00000643237.3	NP_001357587.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BTD	ENST00000643237.3 link	c.1421A>G	p.Tyr474Cys	missense_variant	Exon 4 of 4		NM_001370658.1	ENSP00000495254.2		P43251-4

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152158

Hom.:

Cov.:

show subpopulations

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:

0.00633

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.00000398

AC:

AN:

251422

AF XY:

0.00000736

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000879

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000889

AC:

AN:

1461894

Hom.:

Cov.:

AF XY:

0.00000688

AC XY:

AN XY:

727248

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.0000252

AC:

AN:

39700

South Asian (SAS)

AF:

0.0000116

AC:

AN:

86258

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000989

AC:

AN:

1112012

Other (OTH)

AF:

0.00

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.467

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152276

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74436

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41554

American (AMR)

AF:

0.00

AC:

AN:

15298

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4820

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10608

Middle Eastern (MID)

AF:

0.00340

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

68024

Other (OTH)

AF:

0.00

AC:

AN:

2112

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

ExAC

AF:

0.00000824

AC:

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Biotinidase deficiency

Uncertain:3

Aug 24, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 494 of the BTD protein (p.Tyr494Cys). This variant is present in population databases (rs750598655, gnomAD 0.0009%). This missense change has been observed in individual(s) with biotinidase deficiency (PMID: 26810761, 28498829; Invitae). ClinVar contains an entry for this variant (Variation ID: 554671). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Oct 31, 2017

Counsyl

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Apr 05, 2022

Department of Pathology and Laboratory Medicine, Sinai Health System

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:research

- -

not specified

Uncertain:1

Jun 03, 2024

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: BTD c.1421A>G (p.Tyr474Cys) results in a non-conservative amino acid change in the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251422 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.1421A>G has been reported in the literature in the heterozygous and compound heterozygous states in individuals affected with Biotinidase Deficiency (e.g. Procter_2016, Borsatto_2017, Carvalho_2020, Yilmaz_2024). These data do not allow any conclusion about variant significance. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 28498829, 31801038, 26810761, 38141137). ClinVar contains an entry for this variant (Variation ID: 554671). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.19

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Uncertain

0.11

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.90

.;.;D;.;.;.;.

Eigen

Benign

0.10

Eigen_PC

Benign

-0.066

FATHMM_MKL

Benign

0.19

LIST_S2

Uncertain

0.94

.;D;D;.;.;D;D

M_CAP

Uncertain

0.28

MetaRNN

Pathogenic

0.78

D;D;D;D;D;D;D

MetaSVM

Uncertain

0.48

MutationAssessor

Pathogenic

3.0

.;.;M;.;.;.;.

PhyloP100

2.3

PrimateAI

Benign

0.43

PROVEAN

Pathogenic

-7.5

.;D;.;.;.;D;D

REVEL

Uncertain

0.48

Sift

Uncertain

0.0010

.;D;.;.;.;D;D

Sift4G

Uncertain

0.0050

.;D;.;.;.;D;D

Polyphen

1.0

.;.;D;.;.;.;.

Vest4

0.90, 0.91, 0.87

MutPred

0.63

.;.;Loss of sheet (P = 0.0457);.;.;.;.;

MVP

0.98

MPC

0.41

ClinPred

0.99

GERP RS

2.8

Varity_R

0.41

gMVP

0.91

Mutation Taster

=5/95

disease causing (ClinVar)

(source)

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

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over