rs397514352

Positions:

• chr3-15641932-G-A
• chr3-15641932-G-C

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PM5 PP3_Strong PP5_Moderate

The NM_001370658.1(BTD):​c.274G>A​(p.Glu92Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,016 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 Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E92Q) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: BTD NM_001370658.1 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 10.0

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 10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr3-15641932-G-C is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.988
• PP5: Variant 3-15641932-G-A is Pathogenic according to our data. Variant chr3-15641932-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 2734449.Status of the report is criteria_provided_single_submitter, 1 stars. Variant chr3-15641932-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BTD	NM_001370658.1	c.274G>A	p.Glu92Lys	missense_variant	3/4	ENST00000643237.3	NP_001357587.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
BTD	ENST00000643237.3	c.274G>A	p.Glu92Lys	missense_variant	3/4		NM_001370658.1	ENSP00000495254	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250318 Hom.: 0 AF XY: 0.00000739 AC XY: 1 AN XY: 135256

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000883

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461016 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726746

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.00e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000595

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Biotinidase deficiency Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 19, 2023

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the p.Glu112 amino acid residue in BTD. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9396567). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. 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. This missense change has been observed in individual(s) with biotinidase deficiency (PMID: 14707518). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 112 of the BTD protein (p.Glu112Lys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.84
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	33
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.71	.;.;D;.;.;.;.;D;.;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	.;D;D;.;D;.;D;D;D;D
M_CAP	Pathogenic	0.50	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.0	.;.;H;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D
PrimateAI	Uncertain	0.73	T
PROVEAN	Uncertain	-3.8	.;D;.;.;.;.;D;D;D;.
REVEL	Pathogenic	0.97
Sift	Uncertain	0.0010	.;D;.;.;.;.;D;D;D;.
Sift4G	Uncertain	0.0030	.;D;.;.;.;.;D;D;D;.
Polyphen		1.0	.;.;D;.;.;.;.;.;.;.
Vest4		0.99, 0.99
MutPred		0.96		.;.;Gain of methylation at E112 (P = 0.0053);.;Gain of methylation at E112 (P = 0.0053);.;.;.;.;.;
MVP		0.99
MPC		0.44
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.97
gMVP		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs397514352; hg19: chr3-15683439;