rs398123151

Variant names:

Your query was ambiguous. Multiple possible variants found:

Variant summary

Our verdict is Pathogenic. Variant got 16 ACMG points: 16P and 0B. PM1PM5PP3_StrongPP5_Very_Strong

The NM_000071.3(CBS):c.1006C>T(p.Arg336Cys) variant causes a missense change involving the alteration of a conserved nucleotide. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R336H) has been classified as Pathogenic.

Frequency

Genomes: not found (cov: 0)

Exomes 𝑓: 0.0 ( 0 hom. )

Failed GnomAD Quality Control

Consequence

CBS
NM_000071.3 missense

Scores

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:13O:1

Conservation

PhyloP100: 8.70

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 Pathogenic. Variant got 16 ACMG points.

PM1

In a helix (size 14) in uniprot entity CBS_HUMAN there are 7 pathogenic changes around while only 0 benign (100%) in NM_000071.3

PM5

Other missense variant is known to change same aminoacid residue: Variant chr21-43062343-C-T is described in Lovd as [Pathogenic].

PP3

MetaRNN computational evidence supports a deleterious effect, 0.992

PP5

Variant 21-43062344-G-A is Pathogenic according to our data. Variant chr21-43062344-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 92423.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr21-43062344-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
CBS	NM_000071.3 link	c.1006C>T	p.Arg336Cys	missense_variant	Exon 11 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.1006C>T	p.Arg336Cys	missense_variant	Exon 11 of 17	1	NM_000071.3	ENSP00000381231.4		P35520-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD3 exomes

AF:

0.0000199

AC:

AN:

250690

Hom.:

AF XY:

0.0000147

AC XY:

AN XY:

135676

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:

0.0000442

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

Data not reliable, filtered out with message: AC0;AS_VQSR

AF:

0.00

AC:

AN:

2302

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

1212

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:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

Alfa

AF:

0.0000642

Hom.:

ExAC

AF:

0.0000165

AC:

EpiCase

AF:

0.0000545

EpiControl

AF:

0.00

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:13Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Classic homocystinuria

Pathogenic:7Other:1

Oct 31, 2018

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

May 21, 2020

Revvity Omics, Revvity

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

- -

Sep 26, 2019

Biochemical Molecular Genetic Laboratory, King Abdulaziz Medical City

Significance: Likely pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Aug 25, 2014

Counsyl

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: literature only

- -

Sep 16, 2020

Natera, Inc.

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

- -

Mar 17, 2024

Genomic Medicine Center of Excellence, King Faisal Specialist Hospital and Research Centre

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

Jan 28, 2024

Baylor Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided

Pathogenic:3

Jul 26, 2012

Eurofins Ntd Llc (ga)

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Aug 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jul 20, 2021

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Reported to be a founder mutation in the Qatari population, affecting approximately 1 in 1,8000 births (Gan-Schreier et al., 2010; El Bashir et al., 2015); Functional studies showed reduced activity of R336C in mammalian (Ismail et al., 2019) and E-coli expression systems (Urreizti et al., 2006); Not observed at significant frequency in large population cohorts (Lek et al., 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 27535533, 31240737, 26582918, 30408270, 12815602, 19914636, 27629047, 25218699, 25712383, 7762555, 23685761, 26464485, 10408774, 21517828, 16786517, 21240075, 7967489, 21062078, 16429402, 12124992, 16205833, 19370759, 20455263, 30968424, 31130284) -

HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED

Pathogenic:1

Jan 27, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with cysteine, which is neutral and slightly polar, at codon 336 of the CBS protein (p.Arg336Cys). This variant is present in population databases (rs398123151, gnomAD 0.004%). This missense change has been observed in individual(s) with homocystinuria (PMID: 12815602, 16205833, 21517828). It has also been observed to segregate with disease in related individuals. ClinVar contains an entry for this variant (Variation ID: 92423). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt CBS protein function with a positive predictive value of 95%. Experimental studies have shown that this missense change affects CBS function (PMID: 10408774, 16205833, 16429402, 26464485). This variant disrupts the p.Arg336 amino acid residue in CBS. Other variant(s) that disrupt this residue have been determined to be pathogenic (PMID: 9870207, 23974653, 25218699). This suggests that this residue is clinically significant, and that variants that disrupt this residue are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -

CBS-related disorder

Pathogenic:1

Jul 09, 2024

PreventionGenetics, part of Exact Sciences

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: clinical testing

The CBS c.1006C>T variant is predicted to result in the amino acid substitution p.Arg336Cys. This variant has previously been reported in the homozygous state or with a second causative CBS variant in numerous patients with homocystinuria (Zaidi et al. 2011. PubMed ID: 21517828; Lee et al. 2005. PubMed ID: 16205833; Alcaide et al. 2014. PubMed ID: 25218699; Gaustadnes et al. 2002. PubMed ID: 12124992; de Franchis et al. 1999. PubMed ID: 10408774; Urreizti et al. 2003. PubMed ID: 12815602). This is the most commonly reported causative variant in the CBS gene in individuals in Qatar (El-Said et al. 2006. PubMed ID: 16786517; Zschocke et al. 2009. PubMed ID: 19370759). A different substitution affecting the same amino acid (p.Arg336His) was also reported in patients with homocystinuria (Coude et al.1998. PubMed ID: 9870207; Kumar et al. 2022. PubMed ID: 36065636). In vitro functional studies have shown that both p.Arg336Cys and p.Arg336His substitutions lead to decreased amount of protein and enzyme activity (Lee et al. 2005. PubMed ID: 16205833; Urreizti et al. 2006. PubMed ID: 16429402; Mayfield et al. 2012. PubMed ID: 22267502). This variant is reported in 0.0044% of alleles in individuals of European (Non-Finnish) descent in gnomAD. This variant is interpreted as pathogenic. -

Homocystinuria

Pathogenic:1

Dec 09, 2020

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: CBS c.1006C>T (p.Arg336Cys) results in a non-conservative amino acid change located in the pyridoxal-phosphate dependent enzyme domain (IPR001926) of the encoded protein sequence. Five of five in-silico tools predict a damaging effect of the variant on protein function. The variant allele was found at a frequency of 2e-05 in 250690 control chromosomes (gnomAD). The variant, c.1006C>T, has been reported in the literature in several homozygous and compound heterozygous individuals affected with Homocystinuria (e.g. deFranchis_1999, Urreizti_2003, El-Said_2006, Zaidi_2012); in addition, the variant was identified as a founder mutation in Qatar (El-Said_2006). These data indicate that the variant is very likely to be associated with disease. Multiple publications reported experimental evidence evaluating an impact on protein function, and demonstrated the lack of enzymatic activity (see e.g. deFranchis_1999, Urreizti_2003, Urreizti_2006, Mendes_2015), in addition, recently a transgenic mouse model was also developed with mice showing marked elevation in serum homocysteine (Gupta_2019). Four clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Uncertain

0.42

BayesDel_addAF

Pathogenic

0.50

BayesDel_noAF

Pathogenic

0.59

CADD

Pathogenic

DANN

Pathogenic

1.0

DEOGEN2

Pathogenic

0.99

D;D;D;D

Eigen

Pathogenic

0.90

Eigen_PC

Pathogenic

0.77

FATHMM_MKL

Pathogenic

0.97

LIST_S2

Uncertain

0.95

.;.;.;D

M_CAP

Pathogenic

0.70

MetaRNN

Pathogenic

0.99

D;D;D;D

MetaSVM

Pathogenic

1.1

MutationAssessor

Pathogenic

4.6

H;H;H;H

PrimateAI

Uncertain

0.64

PROVEAN

Pathogenic

-7.8

D;D;D;D

REVEL

Pathogenic

0.97

Sift

Pathogenic

0.0

D;D;D;D

Sift4G

Pathogenic

0.0

D;D;D;D

Polyphen

1.0

D;D;D;D

Vest4

0.98

MVP

0.94

MPC

1.3

ClinPred

1.0

GERP RS

5.3

Varity_R

0.96

gMVP

0.96

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