3-15644722-C-T

Position:

• chr3-15644722-C-T

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM2 PM5 PP3_Strong PP5_Very_Strong

The NM_001370658.1(BTD):​c.806C>T​(p.Ala269Val) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. 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. A269P) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 32)
• Consequence: BTD NM_001370658.1 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:4 U:1
• Conservation: PhyloP100: 6.27

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]

ACMG classification

Verdict is Pathogenic. Variant got 16 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-15644721-G-C is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988
• PP5: Variant 3-15644722-C-T is Pathogenic according to our data. Variant chr3-15644722-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 379232.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BTD	NM_001370658.1	c.806C>T	p.Ala269Val	missense_variant	4/4	ENST00000643237.3	NP_001357587.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BTD	ENST00000643237.3	c.806C>T	p.Ala269Val	missense_variant	4/4		NM_001370658.1	ENSP00000495254	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:4 Uncertain:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Biotinidase deficiency Pathogenic:3 Uncertain:1

Uncertain significance, flagged submission	clinical testing	Counsyl	Mar 29, 2017	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Oct 27, 2021	This sequence change replaces alanine, a(n) neutral and non-polar amino acid, with valine, a(n) neutral and non-polar amino acid, at codon 289 of the BTD protein (p.Ala289Val). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with biotinidase deficiency (PMID: 22698809). ClinVar contains an entry for this variant (Variation ID: 379232). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant disrupts the p.Ala289 amino acid residue in BTD. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10400129, 26810761, 27657684; Invitae). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -
Likely pathogenic, no assertion criteria provided	clinical testing	Natera, Inc.	Oct 01, 2021	- -
Likely pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Feb 26, 2024	- -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Aug 27, 2023

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Also known as p.(A289V) using alternate nomenclature; This variant is associated with the following publications: (PMID: 26810761, 27657684, 10400129, 22698809, Sharma2021[Poster]) -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.74
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	27
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.90	.;.;D;.;.;.;.
Eigen	Pathogenic	0.78
Eigen_PC	Pathogenic	0.71
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.93	.;D;D;.;.;D;D
M_CAP	Pathogenic	0.46	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.3	.;.;M;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Benign	0.46	T
PROVEAN	Uncertain	-3.8	.;D;.;.;.;D;D
REVEL	Pathogenic	0.83
Sift	Uncertain	0.0010	.;D;.;.;.;D;D
Sift4G	Uncertain	0.0030	.;D;.;.;.;D;D
Polyphen		0.99	.;.;D;.;.;.;.
Vest4		0.74, 0.75, 0.72
MutPred		0.85		.;.;Gain of ubiquitination at K286 (P = 0.1688);.;.;.;.;
MVP		0.99
MPC		0.39
ClinPred		0.99	D
GERP RS		5.8
Varity_R		0.64
gMVP		0.96

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

LitVar

Other links and lift over

dbSNP: rs1057520533; hg19: chr3-15686229;