NM_000709.4:c.1036C>T

Variant summary

Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM2PM5PP3_StrongPP5

The NM_000709.4(BCKDHA):​c.1036C>T​(p.Arg346Cys) variant causes a missense change. The variant allele was found at a frequency of 0.00000373 in 1,606,832 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R346H) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 33)
Exomes 𝑓: 0.0000027 ( 0 hom. )

Consequence

BCKDHA
NM_000709.4 missense

Scores

18
1

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:4U:2

Conservation

PhyloP100: 7.20

Publications

5 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: Likely_pathogenic. The variant received 9 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr19-41423039-G-A is described in ClinVar as Pathogenic/Likely_pathogenic. ClinVar VariationId is 93336.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
PP3
MetaRNN computational evidence supports a deleterious effect, 0.959
PP5
Variant 19-41423038-C-T is Pathogenic according to our data. Variant chr19-41423038-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 93335.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
BCKDHANM_000709.4 linkc.1036C>T p.Arg346Cys missense_variant Exon 8 of 9 ENST00000269980.7 NP_000700.1 P12694-1A0A024R0K3
BCKDHANM_001164783.2 linkc.1033C>T p.Arg345Cys missense_variant Exon 8 of 9 NP_001158255.1 P12694Q59EI3

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
BCKDHAENST00000269980.7 linkc.1036C>T p.Arg346Cys missense_variant Exon 8 of 9 1 NM_000709.4 ENSP00000269980.2 P12694-1
ENSG00000255730ENST00000540732.3 linkc.1138C>T p.Arg380Cys missense_variant Exon 9 of 10 2 ENSP00000443246.1 F5H5P2

Frequencies

GnomAD3 genomes
AF:
0.0000131
AC:
2
AN:
152168
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.0000654
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:
0.0000128
AC:
3
AN:
235072
AF XY:
0.0000157
show subpopulations
Gnomad AFR exome
AF:
0.00
Gnomad AMR exome
AF:
0.0000302
Gnomad ASJ exome
AF:
0.00
Gnomad EAS exome
AF:
0.00
Gnomad FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000946
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000275
AC:
4
AN:
1454546
Hom.:
0
Cov.:
35
AF XY:
0.00000277
AC XY:
2
AN XY:
722840
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33338
American (AMR)
AF:
0.00
AC:
0
AN:
43648
Ashkenazi Jewish (ASJ)
AF:
0.0000385
AC:
1
AN:
25956
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39356
South Asian (SAS)
AF:
0.0000236
AC:
2
AN:
84920
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52856
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5756
European-Non Finnish (NFE)
AF:
9.02e-7
AC:
1
AN:
1108600
Other (OTH)
AF:
0.00
AC:
0
AN:
60116
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.513
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.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74458
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
41560
American (AMR)
AF:
0.0000654
AC:
1
AN:
15300
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3472
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5170
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4816
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10616
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
294
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68032
Other (OTH)
AF:
0.00
AC:
0
AN:
2114
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.550
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:
0.00000378
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:4Uncertain:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Maple syrup urine disease type 1A Pathogenic:2
Mar 14, 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. -

Feb 18, 2024
Baylor Genetics
Significance:Likely pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

Maple syrup urine disease Pathogenic:1Uncertain:1
Mar 20, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 346 of the BCKDHA protein (p.Arg346Cys). This variant is present in population databases (rs182923857, gnomAD 0.003%). This missense change has been observed in individual(s) with maple syrup urine disease (PMID: 24772966). ClinVar contains an entry for this variant (Variation ID: 93335). 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) performed at Invitae indicates that this missense variant is expected to disrupt BCKDHA protein function with a positive predictive value of 95%. 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. -

Nov 07, 2021
Genome-Nilou Lab
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Pathogenic:1
Aug 25, 2013
Eurofins Ntd Llc (ga)
Significance:Pathogenic
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not specified Uncertain:1
Jul 08, 2024
Women's Health and Genetics/Laboratory Corporation of America, LabCorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Variant summary: BCKDHA c.1036C>T (p.Arg346Cys) results in a non-conservative amino acid change located in the Dehydrogenase, E1 component domain (IPR001017) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 1.3e-05 in 235072 control chromosomes. c.1036C>T has been reported in the literature as homozygous or compound heterozygous genotype in individuals affected with Maple Syrup Urine Disease (Park_2011, Narayanan_2013). These data indicate that the variant may be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 21844576, 24772966). ClinVar contains an entry for this variant (Variation ID: 93335). Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
0.99
BayesDel_addAF
Pathogenic
0.50
D
BayesDel_noAF
Pathogenic
0.59
CADD
Pathogenic
31
DANN
Pathogenic
1.0
DEOGEN2
Pathogenic
0.88
.;D;.;.
Eigen
Pathogenic
1.0
Eigen_PC
Pathogenic
0.87
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Pathogenic
1.0
D;D;D;D
M_CAP
Pathogenic
0.90
D
MetaRNN
Pathogenic
0.96
D;D;D;D
MetaSVM
Pathogenic
0.95
D
MutationAssessor
Pathogenic
4.8
.;H;.;.
PhyloP100
7.2
PrimateAI
Pathogenic
0.84
D
PROVEAN
Pathogenic
-7.7
D;D;D;D
REVEL
Pathogenic
0.95
Sift
Pathogenic
0.0
D;D;D;D
Sift4G
Pathogenic
0.0
D;D;D;D
Polyphen
1.0
.;D;.;.
Vest4
0.88
MVP
0.94
MPC
2.2
ClinPred
1.0
D
GERP RS
5.8
PromoterAI
-0.0088
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.8
Varity_R
0.93
gMVP
0.91
Mutation Taster
=2/98
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: rs182923857; hg19: chr19-41928943; API