rs769688327
Variant summary
Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1PM2PM5PP3_StrongPP5_Moderate
The NM_000709.4(BCKDHA):c.475C>T(p.Arg159Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000558 in 1,613,394 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 Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R159Q) has been classified as 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 12 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152204Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000400 AC: 1AN: 250236 AF XY: 0.00000738 show subpopulations
GnomAD4 exome AF: 0.00000547 AC: 8AN: 1461190Hom.: 0 Cov.: 34 AF XY: 0.00000550 AC XY: 4AN XY: 726920 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152204Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74346 show subpopulations
ClinVar
Submissions by phenotype
Maple syrup urine disease Pathogenic:1
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 159 of the BCKDHA protein (p.Arg159Trp). This variant is present in population databases (rs769688327, gnomAD 0.0009%). This missense change has been observed in individual(s) with maple syrup urine disease (PMID: 8161368, 28830848). This variant is also known as R114W. ClinVar contains an entry for this variant (Variation ID: 553759). 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. Experimental studies have shown that this missense change affects BCKDHA function (PMID: 11069910). This variant disrupts the p.Arg159 amino acid residue in BCKDHA. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 26257134, 31980395). 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. -
Maple syrup urine disease type 1A Uncertain:1
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. -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at