Genetic Variant CBS:p.Ile435Asn (chr21-43058888-A-T) – ACMG Classification: Uncertain_significance (5 pts)

Variant summary

Our verdict is Uncertain significance. The variant received 5 ACMG points: 5P and 0B. PP2PP3_Strong

The NM_000071.3(CBS):c.1304T>A(p.Ile435Asn) variant causes a missense change involving the alteration of a conserved nucleotide. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I435T) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 0)

Consequence

CBS
NM_000071.3 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 8.84

Publications

12 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: G2P, Orphanet, Labcorp Genetics (formerly Invitae), Myriad Women’s Health, PanelApp Australia, ClinGen, Genomics England PanelApp

CBS links:

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 5 ACMG points.

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.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.993

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CBS	NM_000071.3 link	c.1304T>A	p.Ile435Asn	missense_variant	Exon 14 of 17	ENST00000398165.8	NP_000062.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CBS	ENST00000398165.8 link	c.1304T>A	p.Ile435Asn	missense_variant	Exon 14 of 17	1	NM_000071.3	ENSP00000381231.4

Frequencies

GnomAD3 genomes

Cov.:

GnomAD2 exomes

AF:

0.00

AC:

AN:

177516

AF XY:

0.00

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:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

Cov.:

GnomAD4 genome

Cov.:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.71

BayesDel_addAF

Pathogenic

0.34

BayesDel_noAF

Pathogenic

0.25

CADD

Pathogenic

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.97

D;D;D;D

Eigen

Uncertain

0.46

Eigen_PC

Uncertain

0.40

FATHMM_MKL

Uncertain

0.97

LIST_S2

Benign

0.0

.;.;.;D

M_CAP

Pathogenic

0.61

MetaRNN

Pathogenic

0.99

D;D;D;D

MetaSVM

Uncertain

0.44

MutationAssessor

Pathogenic

3.2

M;M;M;M

PhyloP100

8.8

PrimateAI

Uncertain

0.54

PROVEAN

Pathogenic

-6.1

D;D;D;D

REVEL

Pathogenic

0.91

Sift

Pathogenic

0.0

D;D;D;D

Sift4G

Pathogenic

0.0010

D;D;D;D

Vest4

0.91

ClinPred

1.0

GERP RS

4.7

PromoterAI

0.0054

Neutral

(source)

Varity_R

0.88

gMVP

0.95

Mutation Taster

=12/88

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

Other links and lift over