rs145901144
Variant summary
Our verdict is Pathogenic. The variant received 11 ACMG points: 11P and 0B. PM1PM2PM5PP3_StrongPP5
The NM_000709.4(BCKDHA):c.889C>T(p.Arg297Cys) variant causes a missense change. The variant allele was found at a frequency of 0.0000143 in 1,614,032 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. R297H) 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: Pathogenic. The variant received 11 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BCKDHA | ENST00000269980.7 | c.889C>T | p.Arg297Cys | missense_variant | Exon 7 of 9 | 1 | NM_000709.4 | ENSP00000269980.2 | ||
| ENSG00000255730 | ENST00000540732.3 | c.991C>T | p.Arg331Cys | missense_variant | Exon 8 of 10 | 2 | ENSP00000443246.1 |
Frequencies
GnomAD3 genomes AF: 0.0000197 AC: 3AN: 152182Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000199 AC: 5AN: 251450 AF XY: 0.0000221 show subpopulations
GnomAD4 exome AF: 0.0000137 AC: 20AN: 1461850Hom.: 0 Cov.: 33 AF XY: 0.00000963 AC XY: 7AN XY: 727228 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000197 AC: 3AN: 152182Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74348 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Maple syrup urine disease Pathogenic:2
This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 297 of the BCKDHA protein (p.Arg297Cys). This variant is present in population databases (rs145901144, gnomAD 0.007%). This missense change has been observed in individuals with maple syrup urine disease (PMID: 16786533, 28830848). ClinVar contains an entry for this variant (Variation ID: 555477). 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%. This variant disrupts the p.Arg297 amino acid residue in BCKDHA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 10745006, 17922217, 29306928). 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. -
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Maple syrup urine disease type 1A Pathogenic:1Uncertain:1
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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. -
not specified Uncertain:1
Variant summary: BCKDHA c.889C>T (p.Arg297Cys) results in a non-conservative amino acid change located in the Dehydrogenase, E1 component (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 2e-05 in 251450 control chromosomes (gnomAD). c.889C>T has been reported in the literature in individuals affected with Maple Syrup Urine Disease (examples: Rodriguez-Pombo_2006 and Cheng_2017). 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: 28830848, 16786533). Three submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as VUS (n=1) and pathogenic/likely pathogenic (n=2). 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