3-15644341-C-T

Variant names:

• chr3-15644341-C-T
• rs397514364
• NM_001370658.1:c.425C>T

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5_Very_Strong

The NM_001370658.1(BTD):​c.425C>T​(p.Ala142Val) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,826 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 (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A142P) has been classified as Pathogenic.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000041 (0 hom.)
• Consequence: BTD NM_001370658.1 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:4 U:1
• Conservation: PhyloP100: 7.91
• Publications: 2 publications found

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

ACMG classification

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

• PM1: In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_001370658.1
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-15644340-G-C is described in ClinVar as Pathogenic. ClinVar VariationId is 1343815.Status of the report is criteria_provided_single_submitter, 1 stars.
• 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, 0.929
• PP5: Variant 3-15644341-C-T is Pathogenic according to our data. Variant chr3-15644341-C-T is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 25014.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
BTD	NM_001370658.1	c.425C>T	p.Ala142Val	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	c.425C>T	p.Ala142Val	missense_variant	Exon 4 of 4		NM_001370658.1	ENSP00000495254.2

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 151990 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

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251188 AF XY: 0.00

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: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000410 AC: 6 AN: 1461836 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 AN XY: 727216

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: 26134

East Asian (EAS) AF: 0.00 AC: 0 AN: 39696

South Asian (SAS) AF: 0.00 AC: 0 AN: 86252

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53416

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000540 AC: 6 AN: 1111982

Other (OTH) AF: 0.00 AC: 0 AN: 60392

GnomAD4 genome AF: 0.00000658 AC: 1 AN: 151990 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 74204

African (AFR) AF: 0.00 AC: 0 AN: 41368

American (AMR) AF: 0.00 AC: 0 AN: 15272

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.00 AC: 0 AN: 5190

South Asian (SAS) AF: 0.00 AC: 0 AN: 4780

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10588

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000147 AC: 1 AN: 68010

Other (OTH) AF: 0.00 AC: 0 AN: 2084

Alfa AF: 0.0000197 Hom.: 0

Bravo AF: 0.0000113

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:4 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Biotinidase deficiency Pathogenic:4 Uncertain:1

Nov 22, 2023

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 29, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 162 of the BTD protein (p.Ala162Val). This variant is present in population databases (rs397514364, gnomAD 0.0009%). This missense change has been observed in individual(s) with BTD-related conditions (PMID: 25144890, 27657684). ClinVar contains an entry for this variant (Variation ID: 25014). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt BTD protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Feb 02, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Mar 26, 2018

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. -

Nov 09, 2021

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The BTD c.485C>T; p.Ala162Val variant (rs397514364) is reported in the literature in multiple individuals affected with partial to profound biotinidase deficiency usually found with a second pathogenic variant (Norrgard 1999, Wolf 2017). This variant is reported in ClinVar (Variation ID: 25014) and is only observed on one allele in the Genome Aggregation Database, indicating it is not a common polymorphism. The alanine at codon 162 is highly conserved, and computational analyses predict that this variant is deleterious (REVEL: 0.928). Based on available information, this variant is considered to be 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. Wolf B et al. Successful outcomes of older adolescents and adults with profound biotinidase deficiency identified by newborn screening. Genet Med. 2017 Apr;19(4):396-402. PMID: 27657684. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.75
BayesDel_addAF	Pathogenic	0.50	D
BayesDel_noAF	Pathogenic	0.48
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.67	.;.;D;.;.;.;D;.
Eigen	Pathogenic	0.69
Eigen_PC	Uncertain	0.61
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.94	.;D;D;.;.;D;D;D
M_CAP	Pathogenic	0.31	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.98	D
MutationAssessor	Pathogenic	3.6	.;.;H;.;.;.;.;.
PhyloP100		7.9
PrimateAI	Uncertain	0.63	T
PROVEAN	Uncertain	-3.9	.;D;.;.;.;D;D;D
REVEL	Pathogenic	0.93
Sift	Pathogenic	0.0	.;D;.;.;.;D;D;D
Sift4G	Pathogenic	0.0	.;D;.;.;.;D;D;D
Polyphen		1.0	.;.;D;.;.;.;.;.
Vest4		0.96, 0.97, 0.97
MVP		0.98
MPC		0.42
ClinPred		1.0	D
GERP RS		5.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.94
gMVP		0.97
Mutation Taster		=4/96	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

Other links and lift over

dbSNP: rs397514364; hg19: chr3-15685848; COSMIC: COSV105148888; COSMIC: COSV105148888;