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
Consequence
NM_000709.4 missense
Scores
Clinical Significance
Conservation
Publications
- maple syrup urine diseaseInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
- maple syrup urine disease type 1AInheritance: AR Classification: DEFINITIVE Submitted by: G2P, Myriad Women’s Health, ClinGen
- classic maple syrup urine diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- intermediate maple syrup urine diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- intermittent maple syrup urine diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
- thiamine-responsive maple syrup urine diseaseInheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 9 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BCKDHA | ENST00000269980.7 | c.1036C>T | p.Arg346Cys | missense_variant | Exon 8 of 9 | 1 | NM_000709.4 | ENSP00000269980.2 | ||
| ENSG00000255730 | ENST00000540732.3 | c.1138C>T | p.Arg380Cys | missense_variant | Exon 9 of 10 | 2 | ENSP00000443246.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152168Hom.: 0 Cov.: 33 show subpopulations
GnomAD2 exomes AF: 0.0000128 AC: 3AN: 235072 AF XY: 0.0000157 show subpopulations
GnomAD4 exome AF: 0.00000275 AC: 4AN: 1454546Hom.: 0 Cov.: 35 AF XY: 0.00000277 AC XY: 2AN XY: 722840 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152286Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1AN XY: 74458 show subpopulations
ClinVar
Submissions by phenotype
Maple syrup urine disease type 1A Pathogenic:2
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. -
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Maple syrup urine disease Pathogenic:1Uncertain:1
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. -
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not provided Pathogenic:1
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not specified Uncertain:1
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:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at