rs79761867

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2PP3_StrongPP5

The NM_183050.4(BCKDHB):c.548G>A(p.Arg183Gln) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000479 in 1,461,840 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).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 0.0000048 ( 0 hom. )

Consequence

BCKDHB
NM_183050.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:3U:1

Conservation

PhyloP100: 9.49

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP3

MetaRNN computational evidence supports a deleterious effect, 0.993

PP5

Variant 6-80168945-G-A is Pathogenic according to our data. Variant chr6-80168945-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 527135.We mark this variant Likely_pathogenic, oryginal submissions are: {Likely_pathogenic=3, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
BCKDHB	NM_183050.4 link	c.548G>A	p.Arg183Gln	missense_variant	Exon 5 of 10	ENST00000320393.9	NP_898871.1	P21953-1A0A140VKB3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
BCKDHB	ENST00000320393.9 link	c.548G>A	p.Arg183Gln	missense_variant	Exon 5 of 10	1	NM_183050.4	ENSP00000318351.5	P21953-1
BCKDHB	ENST00000356489.9 link	c.548G>A	p.Arg183Gln	missense_variant	Exon 5 of 11	1		ENSP00000348880.5	P21953-1
BCKDHB	ENST00000369760.8 link	c.548G>A	p.Arg183Gln	missense_variant	Exon 5 of 6	3		ENSP00000358775.4	P21953-2

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.00000398

AC:

AN:

251348

Hom.:

AF XY:

0.00

AC XY:

AN XY:

135856

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:

0.00000880

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000479

AC:

AN:

1461840

Hom.:

Cov.:

AF XY:

0.00000550

AC XY:

AN XY:

727222

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:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000630

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Bravo

AF:

0.00000756

EpiCase

AF:

0.00

EpiControl

AF:

0.0000593

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:3Uncertain:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Maple syrup urine disease

Pathogenic:2

Dec 28, 2021

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 09, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with glutamine, which is neutral and polar, at codon 183 of the BCKDHB protein (p.Arg183Gln). This variant is present in population databases (no rsID available, gnomAD 0.0009%). This missense change has been observed in individuals with maple-syrup urine disease (PMID: 22593002). ClinVar contains an entry for this variant (Variation ID: 527135). 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 BCKDHB protein function with a positive predictive value of 80%. This variant disrupts the p.Arg183 amino acid residue in BCKDHB. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 11448970, 11509994, 21484869). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Maple syrup urine disease type 1B

Pathogenic:1

Feb 01, 2024

Laboratory of Medical Genetics, National & Kapodistrian University of Athens

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: curation

- -

not specified

Uncertain:1

May 17, 2023

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

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: BCKDHB c.548G>A (p.Arg183Gln) results in a conservative amino acid change located in the Transketolase-like, pyrimidine-binding domain (IPR005475) of the encoded protein sequence. Four of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 4e-06 in 251348 control chromosomes. c.548G>A has been reported in the literature as a presumed compound heterozygous genotype (phase not specified) in at-least one individual affected with Maple Syrup Urine Disease (example, Bashyam_2012). A different nucleotide change, namely, c.548G>C (p.Arg183Pro) has also been reported as compound heterozygous genotype in an individual with Maple Syrup Urine Disease (example, Gupta_2015). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publications have been ascertained in the context of this evaluation (PMID: 22593002, 26257134, 28197878). Two clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 and classified the variant as likely pathogenic citing overlapping evidence utilized in the context of this evaluation. Based on the evidence outlined above, the variant was classified as VUS-possibly pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.97

BayesDel_addAF

Pathogenic

0.52

BayesDel_noAF

Pathogenic

0.51

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.91

.;D;D

Eigen

Pathogenic

1.2

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

D;.;D

M_CAP

Pathogenic

0.81

MetaRNN

Pathogenic

0.99

D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.8

H;H;H

PrimateAI

Uncertain

0.77

PROVEAN

Uncertain

-3.9

D;D;D

REVEL

Pathogenic

0.93

Sift

Pathogenic

0.0

D;D;D

Sift4G

Pathogenic

0.0010

D;D;D

Polyphen

1.0

.;D;D

Vest4

0.95

MutPred

0.94

Loss of catalytic residue at S184 (P = 0.1399);Loss of catalytic residue at S184 (P = 0.1399);Loss of catalytic residue at S184 (P = 0.1399);

MVP

1.0

MPC

0.83

ClinPred

1.0

GERP RS

5.1

Varity_R

0.97

gMVP

0.97

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

Details are displayed if max score is > 0.2

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