rs234706

chr21-43065240-G-A

Variant summary

Our verdict is Benign. Variant got -15 ACMG points: 2P and 17B. PM2 BP4_Strong BP6_Very_Strong BP7 BS2

The NM_000071.3(CBS):c.699C>T(p.Tyr233=) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Benign (★★).

• Frequency: Genomes: not found (cov: 16)
• Consequence: CBS NM_000071.3 synonymous
• Clinical Significance: Benign criteria provided, multiple submitters, no conflicts B:15
• Conservation: PhyloP100: -0.907

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]

ACMG classification

Verdict is Benign. Variant got -15 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.62).
• BP6: Variant 21-43065240-G-A is Benign according to our data. Variant chr21-43065240-G-A is described in ClinVar as [Benign]. Clinvar id is 92426.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr21-43065240-G-A is described in Lovd as [Benign]. Variant chr21-43065240-G-A is described in Lovd as [Likely_benign]. Variant chr21-43065240-G-A is described in Lovd as [Pathogenic].
• BP7: Synonymous conserved (PhyloP=-0.907 with no splicing effect.
• BS2: High Homozygotes in GnomAdExome at 10520 AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
CBS	NM_000071.3	c.699C>T	p.Tyr233=	synonymous_variant	8/17	ENST00000398165.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
CBS	ENST00000398165.8	c.699C>T	p.Tyr233=	synonymous_variant	8/17	1	NM_000071.3	P1

Frequencies

GnomAD3 genomes Cov.: 16

GnomAD3 exomes AF: 0.274 AC: 68736 AN: 251310 Hom.: 10520 AF XY: 0.279 AC XY: 37857 AN XY: 135840

Gnomad AFR exome AF: 0.231

Gnomad AMR exome AF: 0.185

Gnomad ASJ exome AF: 0.350

Gnomad EAS exome AF: 0.0230

Gnomad SAS exome AF: 0.249

Gnomad FIN exome AF: 0.277

Gnomad NFE exome AF: 0.345

Gnomad OTH exome AF: 0.288

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 16

Alfa AF: 0.329 Hom.: 11227

Asia WGS AF: 0.147 AC: 512 AN: 3478

ClinVar

Significance: Benign

Submissions summary: Benign:15

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:6

Benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -
Benign, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Mar 12, 2014	- -
Benign, criteria provided, single submitter	clinical testing	GeneDx	Aug 13, 2013	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -
Benign, no assertion criteria provided	clinical testing	Clinical Genetics, Academic Medical Center	-	- -
Benign, no assertion criteria provided	clinical testing	Joint Genome Diagnostic Labs from Nijmegen and Maastricht, Radboudumc and MUMC+	-	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Dec 02, 2014	p.Tyr233Tyr in exon 8 of CBS: This variant is not expected to have clinical sign ificance because it does not alter an amino acid residue and is not located with in the splice consensus sequence. It has been identified in 34% (2960/8600) of E uropean American chromosomes and 23% (1021/4406) of African American chromosomes by the NHLBI Exome Sequencing Project (http://evs.gs.washington.edu/EVS/; dbSNP rs234706). -

Classic homocystinuria Benign:5

Benign, criteria provided, single submitter	clinical testing	Illumina Laboratory Services, Illumina	Mar 06, 2018	This variant was observed in the ICSL laboratory as part of a predisposition screen in an ostensibly healthy population. It had not been previously curated by ICSL or reported in the Human Gene Mutation Database (HGMD: prior to June 1st, 2018), and was therefore a candidate for classification through an automated scoring system. Utilizing variant allele frequency, disease prevalence and penetrance estimates, and inheritance mode, an automated score was calculated to assess if this variant is too frequent to cause the disease. Based on the score and internal cut-off values, a variant classified as benign is not then subjected to further curation. The score for this variant resulted in a classification of benign for this disease. -
Benign, no assertion criteria provided	clinical testing	Natera, Inc.	Sep 16, 2020	- -
Benign, no assertion criteria provided	clinical testing	Diagnostic Laboratory, Department of Genetics, University Medical Center Groningen	-	- -
Benign, no assertion criteria provided	clinical testing	Genome Diagnostics Laboratory, Amsterdam University Medical Center	Dec 05, 2016	- -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Jul 14, 2021	- -

Familial thoracic aortic aneurysm and aortic dissection Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 24, 2014

This alteration is classified as benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

HYPERHOMOCYSTEINEMIA, THROMBOTIC, CBS-RELATED Benign:1

Benign, criteria provided, single submitter

clinical testing

Invitae

Feb 01, 2024

- -

not provided Benign:1

Benign, criteria provided, single submitter

clinical testing

ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories

Nov 29, 2023

- -

Connective tissue disorder Benign:1

Benign, criteria provided, single submitter

clinical testing

Genome Diagnostics Laboratory, The Hospital for Sick Children

Jul 18, 2022

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.62
Cadd	Benign	2.6
Dann	Benign	0.56
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

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

Other links and lift over

dbSNP: rs234706; hg19: chr21-44485350; COSMIC: COSV61441798; COSMIC: COSV61441798;