rs199599175

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong

The NM_000709.4(BCKDHA):​c.757G>A​(p.Ala253Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000496 in 1,614,164 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. A253G) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)
Exomes 𝑓: 0.0000041 ( 0 hom. )

Consequence

BCKDHA
NM_000709.4 missense

Scores

15
3
1

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:4

Conservation

PhyloP100: 5.09

Publications

4 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 18 ACMG points.

PM1
In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 2 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 chr19-41422275-C-G is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 1520107.Status of the report is criteria_provided_single_submitter, 1 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.986
PP5
Variant 19-41422274-G-A is Pathogenic according to our data. Variant chr19-41422274-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 558191.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BCKDHANM_000709.4 linkc.757G>A p.Ala253Thr missense_variant Exon 6 of 9 ENST00000269980.7 NP_000700.1 P12694-1A0A024R0K3
BCKDHANM_001164783.2 linkc.757G>A p.Ala253Thr missense_variant Exon 6 of 9 NP_001158255.1 P12694Q59EI3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BCKDHAENST00000269980.7 linkc.757G>A p.Ala253Thr missense_variant Exon 6 of 9 1 NM_000709.4 ENSP00000269980.2 P12694-1
ENSG00000255730ENST00000540732.3 linkc.859G>A p.Ala287Thr missense_variant Exon 7 of 10 2 ENSP00000443246.1 F5H5P2

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152168
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:
0.000193
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:
0.00000398
AC:
1
AN:
251438
AF XY:
0.00
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.00
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.0000544
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000410
AC:
6
AN:
1461878
Hom.:
0
Cov.:
33
AF XY:
0.00000550
AC XY:
4
AN XY:
727240
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.0000116
AC:
1
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
0.00000450
AC:
5
AN:
1112002
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.417
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:
0.0000131
AC:
2
AN:
152286
Hom.:
0
Cov.:
32
AF XY:
0.00
AC XY:
0
AN XY:
74470
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41564
American (AMR)
AF:
0.00
AC:
0
AN:
15298
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3468
East Asian (EAS)
AF:
0.000193
AC:
1
AN:
5182
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4830
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10620
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68008
Other (OTH)
AF:
0.00
AC:
0
AN:
2110
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.600
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
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.0000545
EpiControl
AF:
0.00

ClinVar

Significance: Pathogenic
Submissions summary: Pathogenic:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Maple syrup urine disease Pathogenic:2
Oct 06, 2022
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 253 of the BCKDHA protein (p.Ala253Thr). For these reasons, this variant has been classified as Pathogenic. 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. ClinVar contains an entry for this variant (Variation ID: 558191). This variant is also known as A209T. This missense change has been observed in individual(s) with maple syrup urine disease (PMID: 8161368, 16786533, 17922217). This variant is present in population databases (rs199599175, gnomAD 0.007%). -

Jul 05, 2023
Baylor Genetics
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Maple syrup urine disease type 1A Pathogenic:2
May 04, 2018
Counsyl
Significance:Likely pathogenic
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. -

Mar 31, 2020
Natera, Inc.
Significance:Likely pathogenic
Review Status:no assertion criteria provided
Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.84
BayesDel_addAF
Pathogenic
0.55
D
BayesDel_noAF
Pathogenic
0.55
CADD
Pathogenic
30
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.88
.;D;.;.
Eigen
Pathogenic
0.92
Eigen_PC
Pathogenic
0.78
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
0.99
D;D;D;D
M_CAP
Pathogenic
0.75
D
MetaRNN
Pathogenic
0.99
D;D;D;D
MetaSVM
Pathogenic
1.1
D
MutationAssessor
Pathogenic
4.4
.;H;.;.
PhyloP100
5.1
PrimateAI
Uncertain
0.67
T
PROVEAN
Uncertain
-3.6
D;D;D;D
REVEL
Pathogenic
0.91
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Uncertain
0.0040
D;D;D;D
Polyphen
1.0
.;D;.;.
Vest4
0.89
MutPred
0.96
Loss of helix (P = 0.2271);.;.;.;
MVP
0.98
MPC
1.8
ClinPred
1.0
D
GERP RS
4.8
Varity_R
0.92
gMVP
0.85
Mutation Taster
=6/94
disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs199599175; hg19: chr19-41928179; API