Genetic Variant BTD:p.Met66Leu (chr3-15635635-A-T) – ACMG Classification: Likely_pathogenic (7 pts)

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1PM2PM5PP2

The NM_001370658.1(BTD):c.196A>T(p.Met66Leu) variant causes a missense change. The variant allele was found at a frequency of 0.00000205 in 1,461,846 control chromosomes in the GnomAD database, with no homozygous occurrence. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. M66R) has been classified as Likely pathogenic.

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

BTD
NM_001370658.1 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 6.25

Publications

0 publications found

Variant links:

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

BTD links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

PM1

In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 3 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 chr3-15635636-T-G is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 156000.

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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BTD	NM_001370658.1 link	c.196A>T	p.Met66Leu	missense_variant	Exon 2 of 4	ENST00000643237.3	NP_001357587.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
BTD	ENST00000643237.3 link	c.196A>T	p.Met66Leu	missense_variant	Exon 2 of 4		NM_001370658.1	ENSP00000495254.2		P43251-4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

0.00000205

AC:

AN:

1461846

Hom.:

Cov.:

AF XY:

0.00000275

AC XY:

AN XY:

727224

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33478

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86254

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53420

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5768

European-Non Finnish (NFE)

AF:

0.00000270

AC:

AN:

1111974

Other (OTH)

AF:

0.00

AC:

AN:

60392

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.42

BayesDel_addAF

Uncertain

0.059

BayesDel_noAF

Benign

-0.15

CADD

Benign

(source)

DANN

Benign

0.96

DEOGEN2

Uncertain

0.58

.;.;D;.;.;.;.;T;.;.

Eigen

Uncertain

0.24

Eigen_PC

Uncertain

0.31

FATHMM_MKL

Uncertain

0.93

LIST_S2

Benign

0.82

.;T;T;.;D;.;T;T;T;D

M_CAP

Uncertain

0.13

MetaRNN

Uncertain

0.66

D;D;D;D;D;D;D;D;D;D

MetaSVM

Uncertain

-0.037

MutationAssessor

Benign

1.3

.;.;L;.;.;.;.;.;.;.

PhyloP100

6.2

PrimateAI

Uncertain

0.57

PROVEAN

Uncertain

-2.6

.;D;.;.;.;.;D;N;D;.

REVEL

Uncertain

0.46

Sift

Benign

0.043

.;D;.;.;.;.;D;T;D;.

Sift4G

Benign

0.14

.;T;.;.;.;.;T;T;T;.

Polyphen

0.77

.;.;P;.;.;.;.;.;.;.

Vest4

0.38, 0.38, 0.38

MutPred

0.63

.;.;Loss of helix (P = 0.1706);.;Loss of helix (P = 0.1706);.;.;.;.;.;

MVP

0.94

MPC

0.080

ClinPred

0.93

GERP RS

4.7

PromoterAI

-0.024

Neutral

(source)

Varity_R

0.59

gMVP

0.88

Mutation Taster

=88/12

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Computational scores

Splicing

Publications

Other links and lift over