3-15641932-G-C

Position:

• chr3-15641932-G-C

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.274G>C​(p.Glu92Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 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 Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E92K) has been classified as Pathogenic.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000048 (0 hom.)
• Consequence: BTD NM_001370658.1 missense
• Clinical Significance: Likely pathogenic criteria provided, multiple submitters, no conflicts P:2
• 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 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 chr3-15641932-G-A is described in Lovd as [Pathogenic].
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.987
• PP5: Variant 3-15641932-G-C is Pathogenic according to our data. Variant chr3-15641932-G-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 24997.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr3-15641932-G-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
BTD	NM_001370658.1	c.274G>C	p.Glu92Gln	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>C	p.Glu92Gln	missense_variant	3/4		NM_001370658.1	ENSP00000495254	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000479 AC: 7 AN: 1461016 Hom.: 0 Cov.: 31 AF XY: 0.00000413 AC XY: 3 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: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Biotinidase deficiency Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 19, 2018

This variant has been observed on the opposite chromosome (in trans) from a pathogenic variant in an individual affected with profound biotinidase deficiency (PMID: 9396567). This finding is consistent with autosomal recessive inheritance, and suggests that this variant contributes to disease. ClinVar contains an entry for this variant (Variation ID: 24997). 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. The observation of one or more missense substitutions at this codon (p.Glu112Gln, p.Glu112Lys) in affected individuals suggests that this may be a clinically significant residue (PMID: 9396567, 14707518). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant is not present in population databases (ExAC no frequency). This sequence change replaces glutamic acid with glutamine at codon 112 of the BTD protein (p.Glu112Gln). The glutamic acid residue is highly conserved and there is a small physicochemical difference between glutamic acid and glutamine. -

not provided Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Quest Diagnostics Nichols Institute San Juan Capistrano

May 25, 2018

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.85
BayesDel_addAF	Pathogenic	0.58	D
BayesDel_noAF	Pathogenic	0.59
CADD	Pathogenic	32
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.71	.;.;D;.;.;.;.;D;.;.
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	.;D;D;.;D;.;D;D;D;D
M_CAP	Pathogenic	0.43	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	0.64	T
PROVEAN	Uncertain	-2.9	.;D;.;.;.;.;D;D;D;.
REVEL	Pathogenic	0.95
Sift	Uncertain	0.0010	.;D;.;.;.;.;D;D;D;.
Sift4G	Uncertain	0.0030	.;D;.;.;.;.;D;D;D;.
Polyphen		1.0	.;.;D;.;.;.;.;.;.;.
Vest4		0.98
MutPred		0.95		.;.;Loss of sheet (P = 0.3635);.;Loss of sheet (P = 0.3635);.;.;.;.;.;
MVP		0.99
MPC		0.42
ClinPred		1.0	D
GERP RS		5.8
Varity_R		0.74
gMVP		0.99

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: rs397514352; hg19: chr3-15683439;