chr21-43066294-C-T

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 4P and 4B. PP3_StrongBS2

The NM_000071.3(CBS):c.400G>A(p.Gly134Arg) variant causes a missense change. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.000081 ( 2 hom., cov: 14)

Exomes 𝑓: 0.000094 ( 13 hom. )

Consequence

CBS
NM_000071.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 6.84

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 0 ACMG points.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.957

BS2

High Homozygotes in GnomAd4 at 2 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CBS	NM_000071.3 link	c.400G>A	p.Gly134Arg	missense_variant	Exon 5 of 17	ENST00000398165.8	NP_000062.1	P35520-1Q9NTF0

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
CBS	ENST00000398165.8 link	c.400G>A	p.Gly134Arg	missense_variant	Exon 5 of 17	1	NM_000071.3	ENSP00000381231.4		P35520-1

Frequencies

GnomAD3 genomes

AF:

0.0000911

AC:

AN:

98808

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.000676

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.000120

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000997

AC:

AN:

250778

Hom.:

AF XY:

0.0000737

AC XY:

AN XY:

135684

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.0000579

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.000708

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000881

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000943

AC:

AN:

986700

Hom.:

Cov.:

AF XY:

0.0000933

AC XY:

AN XY:

503732

show subpopulations

Gnomad4 AFR exome

AF:

0.000305

Gnomad4 AMR exome

AF:

0.000143

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.000840

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000660

Gnomad4 OTH exome

AF:

0.0000687

GnomAD4 genome

AF:

0.0000809

AC:

AN:

98848

Hom.:

Cov.:

AF XY:

0.0000627

AC XY:

AN XY:

47880

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.000452

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.000120

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.0000950

Hom.:

ESP6500AA

AF:

0.00

AC:

ESP6500EA

AF:

0.000233

AC:

ExAC

AF:

0.000123

AC:

EpiCase

AF:

0.000109

EpiControl

AF:

0.0000593

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Classic homocystinuria

Uncertain:1

Sep 16, 2020

Natera, Inc.

Significance: Uncertain significance

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED

Uncertain:1

Aug 11, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with arginine, which is basic and polar, at codon 134 of the CBS protein (p.Gly134Arg). This variant is present in population databases (rs147474549, gnomAD 0.05%). This variant has not been reported in the literature in individuals affected with CBS-related conditions. ClinVar contains an entry for this variant (Variation ID: 212879). Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Tolerated"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

not provided

Uncertain:1

Jun 05, 2018

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The G134R variant of uncertain significance in the CBS gene has been identified in the CBS gene has not been published as pathogenic or been reported as benign to our knowledge. This variant is not observed at a significant frequency in large population cohorts (Lek et al., 2016). The G134R variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. Additionally, this substitution occurs at a position that is conserved across species, and in silico analysis predicts this variant is probably damaging to the protein structure/function. Nevertheless, this variant lacks observation in a significant number of affected individuals, segregation data, and functional evidence, which would further clarify its pathogenicity. Therefore, based on the currently available information, it is unclear whether this variant is pathogenic or rare benign. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.24

BayesDel_addAF

Pathogenic

0.23

BayesDel_noAF

Pathogenic

0.45

CADD

Uncertain

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.99

D;D;D;D;.

Eigen

Uncertain

0.63

Eigen_PC

Uncertain

0.45

FATHMM_MKL

Uncertain

0.88

LIST_S2

Pathogenic

0.99

.;.;.;D;D

M_CAP

Pathogenic

0.92

MetaRNN

Pathogenic

0.96

D;D;D;D;D

MetaSVM

Pathogenic

1.0

MutationAssessor

Pathogenic

4.0

H;H;H;H;.

PrimateAI

Uncertain

0.65

PROVEAN

Pathogenic

-8.0

D;D;D;D;D

REVEL

Pathogenic

0.86

Sift

Uncertain

0.013

D;D;D;D;D

Sift4G

Uncertain

0.023

D;D;D;D;D

Polyphen

1.0

D;D;D;D;.

Vest4

0.89

MutPred

0.84

Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);

MVP

0.92

MPC

1.2

ClinPred

0.97

GERP RS

5.2

Varity_R

0.74

gMVP

0.93

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