rs397514431

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1PM2PP2PP3_StrongPP5_Very_Strong

The NM_001370658.1(BTD):​c.1559A>G​(p.Tyr520Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000187 in 1,607,142 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 Likely pathogenic (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000014 ( 0 hom. )

Consequence

BTD
NM_001370658.1 missense

Scores

14
4
1

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2

Conservation

PhyloP100: 8.67

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Pathogenic. The variant received 17 ACMG points.

PM1
In a hotspot region, there are 12 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 2 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, 0.974
PP5
Variant 3-15645475-A-G is Pathogenic according to our data. Variant chr3-15645475-A-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 25101.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BTDNM_001370658.1 linkc.1559A>G p.Tyr520Cys missense_variant Exon 4 of 4 ENST00000643237.3 NP_001357587.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BTDENST00000643237.3 linkc.1559A>G p.Tyr520Cys missense_variant Exon 4 of 4 NM_001370658.1 ENSP00000495254.2 P43251-4

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152142
Hom.:
0
Cov.:
32
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:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.0000125
AC:
3
AN:
239118
AF XY:
0.0000229
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:
0.0000185
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000137
AC:
2
AN:
1455000
Hom.:
0
Cov.:
32
AF XY:
0.00000276
AC XY:
2
AN XY:
723940
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44718
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
46650
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111960
Other (OTH)
AF:
0.00
AC:
0
AN:
60344
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.500
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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:
1
AN:
152142
Hom.:
0
Cov.:
32
AF XY:
0.0000135
AC XY:
1
AN XY:
74336
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41414
American (AMR)
AF:
0.00
AC:
0
AN:
15288
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5196
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4832
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10602
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68024
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Genome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378
ExAC
AF:
0.00000827
AC:
1

ClinVar

Significance: Pathogenic/Likely pathogenic
Submissions summary: Pathogenic:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Biotinidase deficiency Pathogenic:2
Aug 23, 2024
ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The BTD c.1559A>G; p.Tyr520Cys variant (rs397514431, ClinVar Variation ID: 25101), also known as c.1619A>G; p.Tyr540Cys for NM_000060.2, is reported in the literature in an individual with biotinidase deficiency who was compound heterozygous with a second BTD variant (Norrgard 1999). This variant is only found on 3 alleles in the Genome Aggregation Database (v2.1.1), indicating it is not a common polymorphism. Computational analyses predict that this variant is deleterious (REVEL: 0.96). Based on available information, this variant is considered to be likely pathogenic. References: Norrgard KJ et al. Mutations causing profound biotinidase deficiency in children ascertained by newborn screening in the United States occur at different frequencies than in symptomatic children. Pediatr Res. 1999 Jul;46(1):20-7. PMID: 10400129. -

Aug 04, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

For these reasons, this variant has been classified as Pathogenic. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt BTD protein function. ClinVar contains an entry for this variant (Variation ID: 25101). This missense change has been observed in individual(s) with clinical features of biotinidase deficiency (PMID: 10400129; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. This variant is present in population databases (rs397514431, gnomAD 0.003%). This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 540 of the BTD protein (p.Tyr540Cys). -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.77
BayesDel_addAF
Pathogenic
0.42
D
BayesDel_noAF
Pathogenic
0.47
CADD
Pathogenic
28
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.92
.;.;D;.;.;.;.
Eigen
Pathogenic
0.87
Eigen_PC
Pathogenic
0.83
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.94
.;D;D;.;.;D;D
M_CAP
Pathogenic
0.33
D
MetaRNN
Pathogenic
0.97
D;D;D;D;D;D;D
MetaSVM
Pathogenic
0.97
D
MutationAssessor
Pathogenic
3.1
.;.;M;.;.;.;.
PhyloP100
8.7
PrimateAI
Uncertain
0.55
T
PROVEAN
Pathogenic
-8.2
.;D;.;.;.;D;D
REVEL
Pathogenic
0.96
Sift
Uncertain
0.0010
.;D;.;.;.;D;D
Sift4G
Pathogenic
0.0010
.;D;.;.;.;D;D
Polyphen
1.0
.;.;D;.;.;.;.
Vest4
0.93, 0.93, 0.93
MutPred
0.85
.;.;Loss of catalytic residue at L535 (P = 0.0677);.;.;.;.;
MVP
0.91
MPC
0.47
ClinPred
0.99
D
GERP RS
5.6
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.1
Varity_R
0.78
gMVP
0.96
Mutation Taster
=3/97
disease causing

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

Other links and lift over

dbSNP: rs397514431; hg19: chr3-15686982; API