rs398123496

Variant names:

• chr19-41410817-G-A
• rs398123496
• NM_000709.4:c.288+1G>A

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1_Strong PS3 PM2 PP5_Very_Strong

The NM_000709.4(BCKDHA):​c.288+1G>A variant causes a splice donor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000752 in 1,461,860 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★). ClinVar reports functional evidence for this variant: "SCV000945978: Disruption of this splice site has been observed in individual(s) with maple syrup urine disease (PMID:26901124).".

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: BCKDHA NM_000709.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:10
• Conservation: PhyloP100: 9.26
• Publications: 2 publications found

Genes affected

BCKDHA (HGNC:986): (branched chain keto acid dehydrogenase E1 subunit alpha) The branched-chain alpha-keto acid (BCAA) dehydrogenase (BCKD) complex is an innter mitochondrial enzyme complex that catalyzes the second major step in the catabolism of the branched-chain amino acids leucine, isoleucine, and valine. The BCKD complex consists of three catalytic components: a heterotetrameric (alpha2-beta2) branched-chain alpha-keto acid decarboxylase (E1), a dihydrolipoyl transacylase (E2), and a dihydrolipoamide dehydrogenase (E3). This gene encodes the alpha subunit of the decarboxylase (E1) component. Mutations in this gene result in maple syrup urine disease, type IA. Multiple transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Sep 2009]

BCKDHA Gene-Disease associations (from GenCC):

• maple syrup urine disease

  Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
• maple syrup urine disease type 1A

  Inheritance: AR Classification: DEFINITIVE Submitted by: G2P, ClinGen, Myriad Women’s Health
• classic maple syrup urine disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• intermediate maple syrup urine disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• intermittent maple syrup urine disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• thiamine-responsive maple syrup urine disease

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ENSG00000255730 (HGNC:):

ACMG classification

Our verdict: Pathogenic. The variant received 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.13452914 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV000945978: Disruption of this splice site has been observed in individual(s) with maple syrup urine disease (PMID: 26901124).
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 19-41410817-G-A is Pathogenic according to our data. Variant chr19-41410817-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 93351.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000709.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BCKDHA	NM_000709.4	MANE Select	c.288+1G>A		splice_donor intron	N/A	NP_000700.1	P12694-1
	BCKDHA	NM_001164783.2		c.288+1G>A		splice_donor intron	N/A	NP_001158255.1	Q59EI3

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BCKDHA	ENST00000269980.7	TSL:1 MANE Select	c.288+1G>A		splice_donor intron	N/A	ENSP00000269980.2	P12694-1
	ENSG00000255730	ENST00000540732.3	TSL:2	c.390+1G>A		splice_donor intron	N/A	ENSP00000443246.1	F5H5P2
	BCKDHA	ENST00000919033.1		c.288+1G>A		splice_donor intron	N/A	ENSP00000589092.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.0000159 AC: 4 AN: 251274 AF XY: 0.00000736

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000578

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.000163

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461860 Hom.: 0 Cov.: 33 AF XY: 0.00000413 AC XY: 3 AN XY: 727238

African (AFR) AF: 0.0000299 AC: 1 AN: 33480

American (AMR) AF: 0.000134 AC: 6 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.00 AC: 0 AN: 86258

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53396

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 0.00000270 AC: 3 AN: 1112002

Other (OTH) AF: 0.0000166 AC: 1 AN: 60396

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.0000227

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.00

EpiControl AF: 0.0000593

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
4	-	-	Maple syrup urine disease (4)
4	-	-	Maple syrup urine disease type 1A (4)
2	-	-	not provided (2)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.34	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	1.0	D
PhyloP100		9.3
GERP RS		5.4
PromoterAI		-0.037	Neutral
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.95
SpliceAI score (max)		0.97		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.97		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs398123496; hg19: chr19-41916722;