rs775808731
Variant summary
Our verdict is Likely pathogenic. The variant received 9 ACMG points: 9P and 0B. PM2PM5PP3_StrongPP5
The NM_001918.5(DBT):c.872G>T(p.Arg291Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000434 in 1,613,896 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic 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. R291Q) has been classified as Likely pathogenic.
Frequency
Consequence
NM_001918.5 missense
Scores
Clinical Significance
Conservation
Publications
- maple syrup urine diseaseInheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen
- maple syrup urine disease type 2Inheritance: AR Classification: DEFINITIVE Submitted by: Myriad Women’s Health, G2P
- 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
Frequencies
GnomAD3 genomes AF: 0.0000263 AC: 4AN: 152140Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251456 AF XY: 0.00000736 show subpopulations
GnomAD4 exome AF: 0.00000205 AC: 3AN: 1461756Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1AN XY: 727192 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000263 AC: 4AN: 152140Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74300 show subpopulations
ClinVar
Submissions by phenotype
Maple syrup urine disease Pathogenic:1Uncertain:1
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This sequence change replaces arginine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 291 of the DBT protein (p.Arg291Leu). This variant is present in population databases (no rsID available, gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of maple syrup urine disease (Invitae). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 457147). 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 DBT protein function with a positive predictive value of 95%. For these reasons, this variant has been classified as Pathogenic. -
not specified Uncertain:1
Variant summary: DBT c.872G>T (p.Arg291Leu) results in a non-conservative amino acid change located in the 2-oxoacid dehydrogenase acyltransferase, catalytic domain of the encoded protein sequence. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change. The variant allele was found at a frequency of 4e-06 in 251456 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.872G>T has been observed in one individual affected with Maple Syrup Urine Disease (internal data). Since the penetrance of Maple Syrup Urine Disease (0) due to this variant appears to be lower than expected (0.8), no conclusions can be drawn from these data. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. ClinVar contains an entry for this variant (Variation ID: 457147). Based on the evidence outlined above, the variant was classified as uncertain significance. -
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