rs121965005

Variant names:

• chr6-80167690-T-G
• rs121965005
• NM_183050.4:c.356T>G

Variant summary

Our verdict is Likely pathogenic. The variant received 8 ACMG points: 8P and 0B. PM2 PP2 PP3_Strong PP5

The NM_183050.4(BCKDHB):​c.356T>G​(p.Val119Gly) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (no stars).

• Frequency: Genomes: not found (cov: 31)
• Consequence: BCKDHB NM_183050.4 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1
• Conservation: PhyloP100: 7.66
• Publications: 2 publications found

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

ACMG classification

Our verdict: Likely_pathogenic. The variant received 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 51 curated pathogenic missense variants (we use a threshold of 10). The gene has 5 curated benign missense variants. Gene score misZ: -0.17637 (below the threshold of 3.09). Trascript score misZ: -0.0026186 (below the threshold of 3.09). GenCC associations: The gene is linked to classic maple syrup urine disease, thiamine-responsive maple syrup urine disease, intermittent maple syrup urine disease, intermediate maple syrup urine disease, maple syrup urine disease type 1B, maple syrup urine disease.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.992
• PP5: Variant 6-80167690-T-G is Pathogenic according to our data. Variant chr6-80167690-T-G is described in ClinVar as Pathogenic. ClinVar VariationId is 11939.Status of the report is no_assertion_criteria_provided, 0 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_183050.4. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BCKDHB	NM_183050.4	MANE Select	c.356T>G	p.Val119Gly	missense	Exon 4 of 10	NP_898871.1
	BCKDHB	NM_001424035.1		c.356T>G	p.Val119Gly	missense	Exon 4 of 10	NP_001410964.1
	BCKDHB	NM_000056.5		c.356T>G	p.Val119Gly	missense	Exon 4 of 11	NP_000047.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	BCKDHB	ENST00000320393.9	TSL:1 MANE Select	c.356T>G	p.Val119Gly	missense	Exon 4 of 10	ENSP00000318351.5
	BCKDHB	ENST00000356489.9	TSL:1	c.356T>G	p.Val119Gly	missense	Exon 4 of 11	ENSP00000348880.5
	BCKDHB	ENST00000369760.8	TSL:3	c.356T>G	p.Val119Gly	missense	Exon 4 of 6	ENSP00000358775.4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: no assertion criteria provided

Submissions by phenotype

Maple syrup urine disease type 1B Pathogenic:1

Apr 23, 2004

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.97
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.52
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.90	D
Eigen	Pathogenic	0.95
Eigen_PC	Pathogenic	0.77
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.97	D
M_CAP	Pathogenic	0.80	D
MetaRNN	Pathogenic	0.99	D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	4.5	H
PhyloP100		7.7
PrimateAI	Pathogenic	0.83	D
PROVEAN	Pathogenic	-6.8	D
REVEL	Pathogenic	0.97
Sift	Pathogenic	0.0	D
Sift4G	Pathogenic	0.0	D
Polyphen		1.0	D
Vest4		0.84
MutPred		0.96		Loss of stability (P = 9e-04)
MVP		1.0
MPC		0.88
ClinPred		1.0	D
GERP RS		4.8
Varity_R		0.99
gMVP		0.99
Mutation Taster		=1/99	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs121965005; hg19: chr6-80877407;