3-15644438-C-G

Variant names:

• chr3-15644438-C-G
• rs750363004
• NM_001370658.1:c.522C>G

Variant summary

Our verdict is Pathogenic. The variant received 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_001370658.1(BTD):​c.522C>G​(p.Phe174Leu) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,894 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 (★★). Synonymous variant affecting the same amino acid position (i.e. F174F) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 31)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: BTD NM_001370658.1 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 U:1
• Conservation: PhyloP100: 0.0500
• Publications: 0 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 8 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, 0.949
• PP5: Variant 3-15644438-C-G is Pathogenic according to our data. Variant chr3-15644438-C-G is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 587716.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.522C>G	p.Phe174Leu	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.522C>G	p.Phe174Leu	missense_variant	Exon 4 of 4		NM_001370658.1	ENSP00000495254.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD2 exomes AF: 0.00000795 AC: 2 AN: 251448 AF XY: 0.0000147

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS 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: 0.00000137 AC: 2 AN: 1461894 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727248

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.0000447 AC: 2 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53420

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

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1112012

Other (OTH) AF: 0.00 AC: 0 AN: 60396

GnomAD4 genome Cov.: 31

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000756

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Biotinidase deficiency Pathogenic:2 Uncertain:1

Mar 11, 2023

Baylor Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 02, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces phenylalanine, which is neutral and non-polar, with leucine, which is neutral and non-polar, at codon 194 of the BTD protein (p.Phe194Leu). This variant is present in population databases (no rsID available, gnomAD 0.006%). This missense change has been observed in individual(s) with biotinidase deficiency (PMID: 26810761; Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 587716). 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 with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -

Sep 16, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.98
BayesDel_addAF	Pathogenic	0.25	D
BayesDel_noAF	Pathogenic	0.29
CADD	Benign	21
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.58	.;.;D;.;.;.;T;.
Eigen	Benign	0.035
Eigen_PC	Benign	-0.13
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.76	.;T;T;.;.;T;D;T
M_CAP	Uncertain	0.15	D
MetaRNN	Pathogenic	0.95	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.50	D
MutationAssessor	Pathogenic	3.1	.;.;M;.;.;.;.;.
PhyloP100		0.050
PrimateAI	Uncertain	0.77	T
PROVEAN	Pathogenic	-4.8	.;D;.;.;.;D;D;D
REVEL	Pathogenic	0.81
Sift	Uncertain	0.0050	.;D;.;.;.;D;D;D
Sift4G	Uncertain	0.0090	.;D;.;.;.;D;D;D
Polyphen		1.0	.;.;D;.;.;.;.;.
Vest4		0.90, 0.92, 0.89
MutPred		0.83		.;.;Gain of disorder (P = 0.1786);.;.;.;.;.;
MVP		0.91
MPC		0.43
ClinPred		0.98	D
GERP RS		-1.3
Varity_R		0.86
gMVP		0.92
Mutation Taster		=0/100	disease causing (ClinVar)

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: rs750363004; hg19: chr3-15685945;