rs398123672

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM2PP5

The NM_001918.5(DBT):​c.5C>T​(p.Ala2Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000547 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A2T) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

DBT
NM_001918.5 missense

Scores

1
8
8

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3

Conservation

PhyloP100: 4.35

Publications

0 publications found
Variant links:
Genes affected
DBT (HGNC:2698): (dihydrolipoamide branched chain transacylase E2) The branched-chain alpha-keto acid dehydrogenase complex (BCKD) is an inner-mitochondrial enzyme complex involved in the breakdown of the branched-chain amino acids isoleucine, leucine, and valine. The BCKD complex is thought to be composed of a core of 24 transacylase (E2) subunits, and associated decarboxylase (E1), dehydrogenase (E3), and regulatory subunits. This gene encodes the transacylase (E2) subunit. Mutations in this gene result in maple syrup urine disease, type 2. Alternatively spliced transcript variants have been described, but their biological validity has not been determined. [provided by RefSeq, Jul 2008]
DBT Gene-Disease associations (from GenCC):
  • maple syrup urine disease
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
  • maple syrup urine disease type 2
    Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health, G2P
  • classic maple syrup urine disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • intermediate maple syrup urine disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • intermittent maple syrup urine disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
  • thiamine-responsive maple syrup urine disease
    Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PP5
Variant 1-100249816-G-A is Pathogenic according to our data. Variant chr1-100249816-G-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 94007.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DBTNM_001918.5 linkc.5C>T p.Ala2Val missense_variant Exon 1 of 11 ENST00000370132.8 NP_001909.4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DBTENST00000370132.8 linkc.5C>T p.Ala2Val missense_variant Exon 1 of 11 1 NM_001918.5 ENSP00000359151.3

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000796
AC:
2
AN:
251212
AF XY:
0.00000737
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000547
AC:
8
AN:
1461866
Hom.:
0
Cov.:
31
AF XY:
0.00000413
AC XY:
3
AN XY:
727236
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.0000383
AC:
1
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:
0.00000630
AC:
7
AN:
1111986
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.506
Heterozygous variant carriers
0
1
1
2
2
3
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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.:
32

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:1Uncertain:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Maple syrup urine disease Pathogenic:1Uncertain:2
Nov 07, 2021
Genome-Nilou Lab
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Jun 02, 2020
Centre for Inherited Metabolic Diseases, Karolinska University Hospital
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Sep 01, 2021
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine with valine at codon 2 of the DBT protein (p.Ala2Val). The alanine residue is moderately conserved and there is a small physicochemical difference between alanine and valine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with DBT-related conditions. ClinVar contains an entry for this variant (Variation ID: 94007). 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: "Benign"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided Uncertain:1
Jun 22, 2015
Eurofins Ntd Llc (ga)
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Uncertain
0.55
BayesDel_addAF
Uncertain
0.065
T
BayesDel_noAF
Benign
-0.14
CADD
Pathogenic
27
DANN
Uncertain
1.0
Eigen
Uncertain
0.59
Eigen_PC
Uncertain
0.60
FATHMM_MKL
Benign
0.52
D
LIST_S2
Benign
0.55
.;T
M_CAP
Benign
0.0093
T
MetaRNN
Uncertain
0.55
D;D
MetaSVM
Benign
-0.99
T
PhyloP100
4.4
PrimateAI
Uncertain
0.57
T
PROVEAN
Benign
-0.81
N;N
REVEL
Benign
0.20
Sift
Pathogenic
0.0
D;D
Sift4G
Uncertain
0.012
D;D
Vest4
0.58
MutPred
0.47
Gain of stability (P = 0.0318);Gain of stability (P = 0.0318);
MVP
0.75
MPC
0.58
ClinPred
0.97
D
GERP RS
5.1
PromoterAI
-0.69
Under-expression
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.6
gMVP
0.87
Mutation Taster
=74/26
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs398123672; hg19: chr1-100715372; COSMIC: COSV64496628; COSMIC: COSV64496628; API