rs200137189
Variant summary
Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM1PM2PM5PP3PP5
The NM_000709.4(BCKDHA):c.890G>A(p.Arg297His) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000452 in 1,613,968 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 14/22 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. R297C) 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 8 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BCKDHA | ENST00000269980.7 | c.890G>A | p.Arg297His | missense_variant | Exon 7 of 9 | 1 | NM_000709.4 | ENSP00000269980.2 | ||
| ENSG00000255730 | ENST00000540732.3 | c.992G>A | p.Arg331His | missense_variant | Exon 8 of 10 | 2 | ENSP00000443246.1 |
Frequencies
GnomAD3 genomes AF: 0.0000592 AC: 9AN: 152126Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000756 AC: 19AN: 251442 AF XY: 0.0000736 show subpopulations
GnomAD4 exome AF: 0.0000438 AC: 64AN: 1461842Hom.: 0 Cov.: 33 AF XY: 0.0000468 AC XY: 34AN XY: 727230 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000592 AC: 9AN: 152126Hom.: 0 Cov.: 32 AF XY: 0.0000404 AC XY: 3AN XY: 74310 show subpopulations
Age Distribution
ClinVar
Submissions by phenotype
Maple syrup urine disease type 1A Pathogenic:4Uncertain:1
The BCKDHA c.890G>A p.(Arg297His) missense variant has been identified in at least two individuals with maple syrup urine disease, where the variant was found in a homozygous state (PMID: 29306928; 17922217). This variant is located in a hotspot region with two nearby P/LP variants, [p.(Asp302Ala) and p.(Gly290Arg)] (ClinVar). This variant is not observed at a significant frequency in version 2.1.1 or version 4.0.0 of the Genome Aggregation Database. Multiple lines of computational evidence suggest the variant may impact the gene or gene product. Additionally, a different amino acid substitution at the same codon [p.(Arg297Cys)] has been reported in individuals with maple syrup urine disease (PMID: 28830848; 16786533; ClinVar).This variant was identified in trans with a likely pathogenic variant in this proband with a phenotype consistent with maple syrup urine disease. Based on the available evidence, the c.890G>A p.(Arg297His) variant is classified as likely pathogenic for maple syrup urine disease. -
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. -
The variant is observed at an extremely low frequency in the gnomAD v2.1.1 dataset (total allele frequency: 0.007%). Predicted Consequence/Location: Missense variant Functional studies provide supporting evidence of the variant having a damaging effect on the gene or gene product (PMID: 10745006). In silico tool predictions suggest damaging effect of the variant on gene or gene product [REVEL: 0.96 (>=0.6, sensitivity 0.68 and specificity 0.92); 3Cnet: 0.99 (>=0.6, sensitivity 0.72 and precision 0.9)]. Same nucleotide change resulting in same amino acid change (PMID: 10745006) anda different missense change at the same codon (p.Arg297Cys / PMID: 16786533) have been previously reported to be associated with BCKDHA related disorder (PMID: 10745006).The variant has been reported to be in trans with a pathogenic variant as either compound heterozygous or homozygous in at least one similarly affected unrelated individual (PMID: 17922217). Therefore, this variant is classified as Likely pathogenic according to the recommendation of ACMG/AMP guideline. -
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Maple syrup urine disease Pathogenic:2Uncertain:1
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This sequence change replaces arginine, which is basic and polar, with histidine, which is basic and polar, at codon 297 of the BCKDHA protein (p.Arg297His). This variant is present in population databases (rs200137189, gnomAD 0.1%). This missense change has been observed in individuals with maple syrup urine disease (PMID: 10745006, 17922217, 29306928). ClinVar contains an entry for this variant (Variation ID: 93376). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) 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: 16786533, 28830848). 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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not provided Uncertain:1
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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at