rs753216964

Positions:

chr19-41422163-G-C

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PVS1_StrongPM2PP3_ModeratePP5_Very_Strong

The NM_000709.4(BCKDHA):c.647-1G>C variant causes a splice acceptor change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000868 in 1,613,108 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 (★★).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000089 ( 0 hom. )

Consequence

BCKDHA
NM_000709.4 splice_acceptor

Scores

Splicing: ADA: 0.9999

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:7

Conservation

PhyloP100: 8.88

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 16 ACMG points.

PVS1

Splicing variant, NOT destroyed by nmd, known LOF gene, truncates exone, which is 0.15396114 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP3

Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.

PP5

Variant 19-41422163-G-C is Pathogenic according to our data. Variant chr19-41422163-G-C is described in ClinVar as [Pathogenic]. Clinvar id is 431985.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BCKDHA	NM_000709.4 linkuse as main transcript	c.647-1G>C		splice_acceptor_variant		ENST00000269980.7
BCKDHA	NM_001164783.2 linkuse as main transcript	c.647-1G>C		splice_acceptor_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BCKDHA	ENST00000269980.7 linkuse as main transcript	c.647-1G>C		splice_acceptor_variant		1	NM_000709.4	P1	P12694-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152166

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000147

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.00000402

AC:

AN:

248460

Hom.:

AF XY:

0.00

AC XY:

AN XY:

134674

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00000893

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000890

AC:

AN:

1460942

Hom.:

Cov.:

AF XY:

0.00000963

AC XY:

AN XY:

726762

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000116

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000900

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152166

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74346

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000147

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000151

ExAC

AF:

0.00000824

AC:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:7

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Maple syrup urine disease

Pathogenic:6

Pathogenic, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Feb 24, 2020	Variant summary: BCKDHA c.647-1G>C is located in a canonical splice-site and is predicted to affect mRNA splicing resulting in a significantly altered protein due to either exon skipping, shortening, or inclusion of intronic material. Several computational tools predict a significant impact on normal splicing: Four predict the variant abolishes a 3' acceptor site. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 4e-06 in 248460 control chromosomes. c.647-1G>C has been reported in the literature in individuals affected with Maple syrup urine disease (Strauss_2006, Georgiou_2009). These data indicate that the variant is likely to be associated with disease. At least one publication reports experimental evidence evaluating an impact on protein function. The most pronounced variant effect results in <10% of normal activity. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic/likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Nov 07, 2021	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Aug 18, 2023	- -
Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 13, 2024	This sequence change affects an acceptor splice site in intron 5 of the BCKDHA gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in BCKDHA are known to be pathogenic (PMID: 16786533, 22593002). This variant is present in population databases (rs753216964, gnomAD 0.0009%). Disruption of this splice site has been observed in individuals with maple syrup urine disease (PMID: 19715473, 31980395). This variant is also known as IVS5-1G>C. ClinVar contains an entry for this variant (Variation ID: 431985). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	Myriad Genetics, Inc.	Nov 16, 2021	NM_000709.3(BCKDHA):c.647-1G>C is a canonical splice variant classified as pathogenic in the context of maple syrup urine disease type Ia. c.647-1G>C has been observed in cases with relevant disease (PMID: 19715473, 31980395, 28417071). Functional assessments of this variant are not available in the literature. c.647-1G>C has been observed in population frequency databases (ExAC: 0.002%). In summary, NM_000709.3(BCKDHA):c.647-1G>C is a canonical splice variant that has internal structural support for pathogenicity and has been observed more frequently in cases with the relevant disease than in healthy populations. Please note: this variant was assessed in the context of healthy population screening. -
Pathogenic, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Dec 21, 2021	- -

not provided

Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

May 21, 2019

Canonical splice site variant predicted to result in an in-frame deletion of a critical region.; Not observed at a significant frequency in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 19715473, 28417071, 25525159, 29789446, 26901124, 31980395) -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.24

BayesDel_noAF

Uncertain

0.11

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.88

FATHMM_MKL

Pathogenic

0.99

MutationTaster

Benign

1.0

D;D

GERP RS

4.8

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.95

SpliceAI score (max)

0.98

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.72

Position offset: 22

DS_AL_spliceai

0.98

Position offset: 1

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over