rs769688327

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PM2PM5PP3_StrongPP5_Moderate

The NM_000709.4(BCKDHA):​c.475C>T​(p.Arg159Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,394 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging 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. R159Q) has been classified as Pathogenic.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000055 ( 0 hom. )

Consequence

BCKDHA
NM_000709.4 missense

Scores

17
1
1

Clinical Significance

Pathogenic criteria provided, single submitter P:1U:1

Conservation

PhyloP100: 3.38

Publications

1 publications found
Variant links:
Genes affected
BCKDHA (HGNC:986): (branched chain keto acid dehydrogenase E1 subunit alpha) The branched-chain alpha-keto acid (BCAA) dehydrogenase (BCKD) complex is an innter mitochondrial enzyme complex that catalyzes the second major step in the catabolism of the branched-chain amino acids leucine, isoleucine, and valine. The BCKD complex consists of three catalytic components: a heterotetrameric (alpha2-beta2) branched-chain alpha-keto acid decarboxylase (E1), a dihydrolipoyl transacylase (E2), and a dihydrolipoamide dehydrogenase (E3). This gene encodes the alpha subunit of the decarboxylase (E1) component. Mutations in this gene result in maple syrup urine disease, type IA. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Sep 2009]
BCKDHA Gene-Disease associations (from GenCC):
  • maple syrup urine disease
    Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • maple syrup urine disease type 1A
    Inheritance: AR Classification: DEFINITIVE Submitted by: G2P, Myriad Women’s Health, ClinGen
  • 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: Pathogenic. The variant received 12 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain in NM_000709.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr19-41414149-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 204378.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.99
PP5
Variant 19-41414148-C-T is Pathogenic according to our data. Variant chr19-41414148-C-T is described in ClinVar as Pathogenic. ClinVar VariationId is 553759.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BCKDHANM_000709.4 linkc.475C>T p.Arg159Trp missense_variant Exon 4 of 9 ENST00000269980.7 NP_000700.1
BCKDHANM_001164783.2 linkc.475C>T p.Arg159Trp missense_variant Exon 4 of 9 NP_001158255.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BCKDHAENST00000269980.7 linkc.475C>T p.Arg159Trp missense_variant Exon 4 of 9 1 NM_000709.4 ENSP00000269980.2
ENSG00000255730ENST00000540732.3 linkc.577C>T p.Arg193Trp missense_variant Exon 5 of 10 2 ENSP00000443246.1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152204
Hom.:
0
Cov.:
32
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000400
AC:
1
AN:
250236
AF XY:
0.00000738
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:
0.00000886
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000547
AC:
8
AN:
1461190
Hom.:
0
Cov.:
34
AF XY:
0.00000550
AC XY:
4
AN XY:
726920
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39698
South Asian (SAS)
AF:
0.0000232
AC:
2
AN:
86258
European-Finnish (FIN)
AF:
0.0000189
AC:
1
AN:
52790
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1111956
Other (OTH)
AF:
0.00
AC:
0
AN:
60382
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.456
Heterozygous variant carriers
0
1
2
2
3
4
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
AF:
0.00000657
AC:
1
AN:
152204
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74346
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41452
American (AMR)
AF:
0.00
AC:
0
AN:
15274
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5202
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10622
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68036
Other (OTH)
AF:
0.00
AC:
0
AN:
2090
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.425
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:1Uncertain:1
Revision: criteria provided, single submitter
LINK: link

Submissions by phenotype

Maple syrup urine disease Pathogenic:1
Feb 03, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 159 of the BCKDHA protein (p.Arg159Trp). This variant is present in population databases (rs769688327, gnomAD 0.0009%). This missense change has been observed in individual(s) with maple syrup urine disease (PMID: 8161368, 28830848). This variant is also known as R114W. ClinVar contains an entry for this variant (Variation ID: 553759). 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on BCKDHA protein function. Experimental studies have shown that this missense change affects BCKDHA function (PMID: 11069910). This variant disrupts the p.Arg159 amino acid residue in BCKDHA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 26257134, 31980395). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

Maple syrup urine disease type 1A Uncertain:1
Sep 06, 2017
Counsyl
Significance:Uncertain significance
Review Status:no assertion criteria provided
Collection Method:clinical testing

This submission and the accompanying classification are no longer maintained by the submitter. For more information on current observations and classification, please contact variantquestions@myriad.com. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
1.0
BayesDel_addAF
Pathogenic
0.56
D
BayesDel_noAF
Pathogenic
0.57
CADD
Pathogenic
33
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.88
.;D;.;.
Eigen
Pathogenic
0.95
Eigen_PC
Pathogenic
0.80
FATHMM_MKL
Uncertain
0.91
D
LIST_S2
Pathogenic
1.0
D;D;D;D
M_CAP
Pathogenic
0.80
D
MetaRNN
Pathogenic
0.99
D;D;D;D
MetaSVM
Pathogenic
0.92
D
MutationAssessor
Pathogenic
4.8
.;H;.;.
PhyloP100
3.4
PrimateAI
Pathogenic
0.81
D
PROVEAN
Pathogenic
-7.6
D;D;D;D
REVEL
Pathogenic
0.94
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Pathogenic
0.0010
D;D;D;D
Polyphen
1.0
.;D;.;.
Vest4
0.99
MutPred
0.93
Loss of helix (P = 0.0558);.;.;.;
MVP
0.99
MPC
1.9
ClinPred
1.0
D
GERP RS
4.7
Varity_R
0.98
gMVP
0.99
Mutation Taster
=3/97
disease causing

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: rs769688327; hg19: chr19-41920053; API