rs1400121541

Variant names:

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1PM2PP5_Very_Strong

The NM_183050.4(BCKDHB):c.348delA(p.Asp117IlefsTer113) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000373 in 1,606,452 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 31)

Exomes 𝑓: 0.0000028 ( 0 hom. )

Consequence

BCKDHB
NM_183050.4 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 0.690

Publications

1 publications found

Variant links:

Genes affected

BCKDHB (HGNC:987): (branched chain keto acid dehydrogenase E1 subunit beta) This gene encodes the E1 beta subunit of branched-chain keto acid dehydrogenase, which is a multienzyme complex associated with the inner membrane of mitochondria. This enzyme complex functions in the catabolism of branched-chain amino acids. Mutations in this gene have been associated with maple syrup urine disease (MSUD), type 1B, a disease characterized by a maple syrup odor to the urine in addition to mental and physical retardation and feeding problems. Alternative splicing at this locus results in multiple transcript variants. [provided by RefSeq, Jan 2016]

BCKDHB Gene-Disease associations (from GenCC):

maple syrup urine disease type 1B
Inheritance: AR Classification: DEFINITIVE Submitted by: ClinGen, G2P, Myriad Women’s Health
maple syrup urine disease
Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
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

BCKDHB links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

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

PVS1

Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 6-80167678-GA-G is Pathogenic according to our data. Variant chr6-80167678-GA-G is described in ClinVar as Pathogenic. ClinVar VariationId is 457148.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BCKDHB	NM_183050.4 link	c.348delA	p.Asp117IlefsTer113	frameshift_variant	Exon 4 of 10	ENST00000320393.9	NP_898871.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein
BCKDHB	ENST00000320393.9 link	c.348delA	p.Asp117IlefsTer113	frameshift_variant	Exon 4 of 10	1	NM_183050.4	ENSP00000318351.5
BCKDHB	ENST00000356489.9 link	c.348delA	p.Asp117IlefsTer113	frameshift_variant	Exon 4 of 11	1		ENSP00000348880.5
BCKDHB	ENST00000369760.8 link	c.348delA	p.Asp117IlefsTer99	frameshift_variant	Exon 4 of 6	3		ENSP00000358775.4

Frequencies

GnomAD3 genomes

AF:

0.0000132

AC:

AN:

151922

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000655

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:

0.00

Gnomad OTH

AF:

0.000480

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

250924

AF XY:

0.0000147

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000868

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000164

GnomAD4 exome

AF:

0.00000275

AC:

AN:

1454530

Hom.:

Cov.:

AF XY:

0.00000276

AC XY:

AN XY:

724066

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33264

American (AMR)

AF:

0.0000895

AC:

AN:

44716

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26106

East Asian (EAS)

AF:

0.00

AC:

AN:

39610

South Asian (SAS)

AF:

0.00

AC:

AN:

86042

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53366

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5754

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

1105496

Other (OTH)

AF:

0.00

AC:

AN:

60176

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.475

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000132

AC:

AN:

151922

Hom.:

Cov.:

AF XY:

0.0000270

AC XY:

AN XY:

74186

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.00

AC:

AN:

41326

American (AMR)

AF:

0.0000655

AC:

AN:

15256

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5186

South Asian (SAS)

AF:

0.00

AC:

AN:

4814

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10566

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.00

AC:

AN:

67996

Other (OTH)

AF:

0.000480

AC:

AN:

2084

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.00000000770867), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.400

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.00

Hom.:

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Maple syrup urine disease

Pathogenic:4

Nov 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change creates a premature translational stop signal (p.Asp117Ilefs*113) in the BCKDHB gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in BCKDHB are known to be pathogenic (PMID: 16786533, 22593002). This variant is present in population databases (no rsID available, gnomAD 0.009%). This premature translational stop signal has been observed in individuals with maple syrup urine disease (PMID: 16786533, 26232051). ClinVar contains an entry for this variant (Variation ID: 457148). For these reasons, this variant has been classified as Pathogenic. -

Nov 07, 2021

Genome-Nilou Lab

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Sep 16, 2019

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Variant summary: BCKDHB c.348delA (p.Asp117IlefsX113) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic by our laboratory (eg. c.853C>T, p.Arg285X; c.970C>T, p.Arg324X). The variant allele was found at a frequency of 1.6e-05 in 250924 control chromosomes (gnomAD). c.348delA has been reported in the literature in compound heterozygous and homozygous individuals affected with Maple syrup urine disease (Couce_2015, Rodriguez-Pombo_2006). These data indicate that the variant may be associated with disease. Enzymatic activity in an individual homozygous for the variant was determined to be 14% and in an individual compound heterozygous for the variant and another variant was determined to be 1.3%. A ClinVar submitter (evaluation after 2014) cites the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Nov 10, 2022

Laboratorio de Genetica e Diagnostico Molecular, Hospital Israelita Albert Einstein

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

ACMG classification criteria: PVS1 very strong, PM2 supporting, PM3 strong, PP4 -

Maple syrup urine disease type 1B

Pathogenic:1

May 24, 2021

Natera, Inc.

Significance:Pathogenic

Review Status:no assertion criteria provided

Collection Method:clinical testing

- -

Maple syrup urine disease type 1A

Pathogenic:1

Jan 12, 2024

Baylor Genetics

Significance:Pathogenic

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

PhyloP100

0.69

Mutation Taster

=6/194

disease causing (ClinVar)

(source)

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.26

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.26

Position offset: 6

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

Publications

You must be logged in to view publications. This limit was set because tens of millions (!) of queries from AI bots are generated daily.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over