NM_000709.4:c.757G>A
Variant summary
Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PM1PM2PM5PP3_StrongPP5_Very_Strong
The NM_000709.4(BCKDHA):c.757G>A(p.Ala253Thr) variant causes a missense change. The variant allele was found at a frequency of 0.00000496 in 1,614,164 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 Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A253G) 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 18 ACMG points.
Transcripts
RefSeq
Ensembl
| Gene | Transcript | HGVSc | HGVSp | Effect | Exon rank | TSL | MANE | Protein | Appris | UniProt |
|---|---|---|---|---|---|---|---|---|---|---|
| BCKDHA | ENST00000269980.7 | c.757G>A | p.Ala253Thr | missense_variant | Exon 6 of 9 | 1 | NM_000709.4 | ENSP00000269980.2 | ||
| ENSG00000255730 | ENST00000540732.3 | c.859G>A | p.Ala287Thr | missense_variant | Exon 7 of 10 | 2 | ENSP00000443246.1 |
Frequencies
GnomAD3 genomes AF: 0.0000131 AC: 2AN: 152168Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.00000398 AC: 1AN: 251438 AF XY: 0.00 show subpopulations
GnomAD4 exome AF: 0.00000410 AC: 6AN: 1461878Hom.: 0 Cov.: 33 AF XY: 0.00000550 AC XY: 4AN XY: 727240 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.0000131 AC: 2AN: 152286Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0AN XY: 74470 show subpopulations
ClinVar
Submissions by phenotype
Maple syrup urine disease Pathogenic:2
This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 253 of the BCKDHA protein (p.Ala253Thr). For these reasons, this variant has been classified as Pathogenic. 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. ClinVar contains an entry for this variant (Variation ID: 558191). This variant is also known as A209T. This missense change has been observed in individual(s) with maple syrup urine disease (PMID: 8161368, 16786533, 17922217). This variant is present in population databases (rs199599175, gnomAD 0.007%). -
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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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Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at