Genetic Variant CBS:p.Thr296Arg (chr21-43063020-G-C) – ACMG Classification: Uncertain_significance (3 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 3 ACMG points: 3P and 0B. PM1PP2

The NM_000071.3(CBS):c.887C>G(p.Thr296Arg) variant causes a missense change. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T296M) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 0)

Consequence

CBS
NM_000071.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 4.77

Publications

0 publications found

Variant links:

Genes affected

CBS (HGNC:1550): (cystathionine beta-synthase) The protein encoded by this gene acts as a homotetramer to catalyze the conversion of homocysteine to cystathionine, the first step in the transsulfuration pathway. The encoded protein is allosterically activated by adenosyl-methionine and uses pyridoxal phosphate as a cofactor. Defects in this gene can cause cystathionine beta-synthase deficiency (CBSD), which can lead to homocystinuria. This gene is a major contributor to cellular hydrogen sulfide production. Multiple alternatively spliced transcript variants have been found for this gene. [provided by RefSeq, Feb 2016]

CBS Gene-Disease associations (from GenCC):

classic homocystinuria
Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), G2P, ClinGen, Orphanet, Myriad Women’s Health, Genomics England PanelApp

CBS links:

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 3 ACMG points.

PM1

In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 5 uncertain in NM_000071.3

PP2

Missense variant in the gene, where a lot of missense mutations are associated with disease in ClinVar. The gene has 107 curated pathogenic missense variants (we use a threshold of 10). The gene has 4 curated benign missense variants. Gene score misZ: 0.8318 (below the threshold of 3.09). Trascript score misZ: NaN (below the threshold of 3.09). GenCC associations: The gene is linked to classic homocystinuria.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000071.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CBS	NM_000071.3	MANE Select	c.887C>G	p.Thr296Arg	missense	Exon 10 of 17	NP_000062.1	P35520-1
CBS	NM_001178008.3		c.887C>G	p.Thr296Arg	missense	Exon 10 of 17	NP_001171479.1	P35520-1
CBS	NM_001178009.3		c.887C>G	p.Thr296Arg	missense	Exon 10 of 18	NP_001171480.1	P35520-1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
CBS	ENST00000398165.8	TSL:1 MANE Select	c.887C>G	p.Thr296Arg	missense	Exon 10 of 17	ENSP00000381231.4	P35520-1
CBS	ENST00000352178.9	TSL:1	c.887C>G	p.Thr296Arg	missense	Exon 10 of 17	ENSP00000344460.5	P35520-1
CBS	ENST00000359624.7	TSL:1	c.887C>G	p.Thr296Arg	missense	Exon 10 of 18	ENSP00000352643.3	P35520-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.0000716

AC:

AN:

251398

AF XY:

0.0000589

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 FIN exome

AF:

0.000324

Gnomad NFE exome

AF:

0.0000879

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

Cov.:

GnomAD4 genome

Cov.:

ExAC

AF:

0.000107

AC:

ClinVar

ClinVar submissions

Significance:Uncertain significance

Revision:criteria provided, multiple submitters, no conflicts

View on ClinVar

Pathogenic

VUS

Benign

Condition

Classic homocystinuria (1)

Familial thoracic aortic aneurysm and aortic dissection (1)

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Uncertain

0.038

BayesDel_noAF

Uncertain

0.020

CADD

Benign

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.92

Eigen

Benign

-0.28

Eigen_PC

Benign

-0.29

FATHMM_MKL

Uncertain

0.92

LIST_S2

Uncertain

0.93

M_CAP

Pathogenic

0.32

MetaRNN

Uncertain

0.52

MetaSVM

Uncertain

0.62

MutationAssessor

Benign

1.3

PhyloP100

4.8

PrimateAI

Benign

0.45

PROVEAN

Uncertain

-3.7

REVEL

Uncertain

0.44

Sift

Benign

0.064

Sift4G

Benign

0.15

Polyphen

0.22

Vest4

0.50

MutPred

0.44

Loss of glycosylation at T299 (P = 0.0901)

MVP

0.84

MPC

0.43

ClinPred

0.17

GERP RS

3.8

Varity_R

0.71

gMVP

0.91

Mutation Taster

=32/68

disease causing

(source)

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

Publications

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over